Aephraim M. Steinberg

Quantum physicist

Experimental quantum measurement, ultracold atoms,
quantum optics, and quantum information

Office: MP 1103
Telephone: (416) 978-0713
Fax: (416) 978-2537
Labs: MP 054/056
Telephone: (416) 946-3162
e-mail: steinberg at

News, Cartoons and photos
Talks and posters
Post-Docs and Visitors
Graduate Students
Undergraduate Students

Brief CV:
B.S., Yale University (1988); Research Assistant, LKB (then LSH), Ecole Normale Supérieure, Paris (1989); Ph.D., U.C. Berkeley (1994); Chateaubriand Fellow, LKB, Université de Paris VI (1994); NRC Fellow, National Institute of Standards and Technology (1995-96); Asst. Prof., University of Toronto (1996-2001); Polanyi Prize, 1997; PREA award, 1999; Assoc. Prof., U of T (2001-2005); Gastprofessor, Univ. of Vienna (Fall 2003); Chercheur invité, Institut d'Optique, Orsay (Spring 2004); Full Prof., University of Toronto (2005-); CAP Herzberg Medal, 2006; RSC Rutherford Medal, 2006; McLean Fellow, 2007; Steacie Fellow, 2007; Fellow of the Optical Society of America, the American Physical Society, the Institute of Physics (UK) and the Canadian Institute for Advanced Research; Visiting Scholar, Univ. of Queensland (Nov 2008 - Feb 2009); JSPS Fellow and Visiting Professor (Hokkaido University), March - June 2011; FRSC (2016).
Click here for scientific genealogy
Click here for academic ontogeny

Links to a little light reading (eine kleine Lichtphysik)

My (paean to)/(rant about) LIGO:

May 2016: a new MOT is born, on the Rydberg-EIT-LMI apparatus!
(Cf. the original 1997 MOT from the predecessor apparatus)

April 2016: In laymen's terms, the peaks on the scope behind Josiah represent a cloud of ill-behaved Rubidium atoms being told "I know you want to steal my 780nm photons, but you better think twice, because if you do, there's a good probability (amplitude) that my big blue laser over here will grab your beloved valence electron and whisk it so unimaginably far away from you that you'll despair of ever seeing it again.
"So first you gotta ask yourself, Do you feel lucky, punk?"
So far, about 90% of the atoms still feel lucky, but that's not bad for a start.
Realism Is For People Who Can't Take Their Nonlocality

What happens when you cross the beams: light-light interactions at the single-photon level
(Or watch the video abstract by Research Square.)

A Canary in a Quantum Coal Mine

Putting the squeeze on Schrödinger's cat

This One Goes To Eleven.
(The story of our latest paper on quantum metrology.)

The Search for the "Bloch Boson"
(The story of our recent paper on Bose-Einstein condensates.)

The BBC's description of our measurement of photon 'trajectories';
Chad Orzel's more scientifically accurate yet readable description of the same work;
Mitch Benn's musical(!) rendition of the same work;
and the full paper.
(See also this earlier paper with Howard Wiseman.)

Justin Mullins's New Scientist article on our work on closed timelike curves;
the original article

When you see without looking, can you trust what you see?;
a very funny take on this in the Toronto Star;
and the "physics and philosophy" section(!) in the Economist; oh, and, the technical article if you're up for that.

"Mapping a new world for light";
and the actual article.

Some miscellaneous recent news (see also full list of publications!) :

9 January 2017: We welcome Kent Bonsma-Fisher, the newest member of the group!

20 December 2016: My Physics Today column about Ryo Okamoto's beautiful quantum-shutter experiment has come out.

15 December 2016: Our paper on Quantum Thermometry has appeared in Scientific Reports!

21 June 2016: Alum Dylan Mahler has been appointed Lecturer of Quantum Engineering at the University of Bristol! Congratulations, and best of luck in your new position!

2 May 2016: Congrats to Josiah, Shaun, and Alex on observing cold Rubidium atoms in their new chamber for the first time!!! Now we're ready to do some science! (See above for photo; and compare the previous iteration of this apparatus, back in 1997!)

28 April 2016: Our paper on how well EIT-based nonlinearities work even for pulses shorter than the EIT response time appeared today in PRL! Congrats to Greg, Amir, Matin, and all the rest of the group!

24 April 2016: Scott Aaronson and I were interviewed on the CBC about quantum computing, and given substantially more time than in this Macleans's attempt to revisit the Justin Trudeau"Quantumgate".

20 April 2016: Josiah has succeeded in observing a Rydberg-EIT signal in our new setup! (See above for photos, and Clint Eastwood's explication of the effect.)

19 February 2016: Nice work, Dylan and Lee -- and Kent, Lydia, Kevin, and Howard! Our paper on reconstructing "surreal" Bohmian trajectories has appeared in Science Advances

21 January 2016: Congrats to Amir and Greg on the publication of their work showing that narrow EIT windows can offer an enhancement in nonlinearity even for broadband pulses!

15 January 2016: Congratulations to Shreyas Potnis on a successful PhD defense, and also the first in the new tradition of public PhD defenses at U of T Physics!

18 November 2015: Congratulations to Greg Dmochowski on successfully defending his Ph.D. thesis!

10 November 2015: Congratulations to alum Krister Shalm on submitting not one, but two, papers (A and B) on loophole-free tests of local realism (I guess even if you don't leave any loopholes, you still can't be too careful)! This may not earn him the Nobel Prize I keep predicting one of my students will earn (see family tree), but I think he's got a good shot at a pretty nice share of a Breakthrough Prize! Congratulations on taking part (and a leading role) in a truly historic set of experiments, Krister!

28 October 2015: Congratulations to Matin on successfully defending his Ph.D.!

24 August 2015: Amir, Matin, and Greg's work on observing nonlinear optics at the single-photon level has appeared in Nature Physics, DOI: 10.1038/nphys3433 .
(See also the video abstract by Research Square.)

27 April 2015: Congratulations to Lee, Chao, Dylan, Alex, John, and Marco on our first paper in Optica, this work on stimulated-emission entanglement tomography!

21 January 2015: The second-closest thing to an epistemology paper I've ever come to writing has finally (!) been published. Also, it appears the editors have seen fit to bestow upon me an honorary faculty position in Haifa!

6 January 2015: Happy New Year! Business Insider (a magazine I never knew anything about before, but now realize is one of the premiere news sources on the planet) has joined Physics World in listing our Quantum Data Compression experiment as one of the top 11 physics discoveries of 2014!

24 December 2014: A Christmas Present! Our Note on different definitions of momentum disturbance, after a protracted and unpleasant interaction with Phys Rev, has instead been accepted for publication in Quantum Studies: Mathematics and Foundations!

18 December 2014: Congratulations to Hugo on a very successful M.Sc. defense!

12 December 2014: Our data compression work has been selected as one of the top ten Physics Breakthroughs of the Year according to Physics World! (See related story on BBC.) Congratulations, every one!

2 December 2014: We are happy to announce that Dylan Mahler has joined the swelling ranks of Ph.D. graduates from our group! Nice work, Dylan!

1 December 2014: Our work on interfering exciton-polariton condensates created at different times has, after dogged persistence, finally come out! Congratulations to Alex, and the whole team!

11 November 2014: Hearty congratulations go out to Amir on his success at his SGS thesis defense!

7 November 2014: Our PRX on optimizing the choice of states for quantum metrology has been published!

October 2014: Our work on the Heisenberg measurement-disturbance relationship [see PRL 109, 100404 (12)] is discussed in the article in the October 2014 issue of La Recherche.

17 October 2014: Our PRL on quantum data compression has finally appeared, along with a nice Focus article by David Lindley. [Update: this work was chosen by Physics World as one of the top ten physics breakthroughs of 2014! Congratulations to the whole team!]

9 October 2014: Congratulations to Dylan on an excellent performance at his departmental thesis defense!

9 October 2014: Apparently, publication of our PRL on data compression is getting bumped another week, to make room for coverage of the Chemistry Nobel Prize. I guess that's fair.

7 October 2014: Congratulations, Xingxing, Amir, & Alex, on the publication of your Optics Express article on a Quantum CDMA channel!

29 September 2014: Our paper on Quantum Data Compression (expected to be published online at PRL around Wednesday) has already been reported on in the pages of Physics World and Nature!

23 September 2014: Congratulations to Ginelle and Josiah on successfully completing their M.Sc. degrees!

18 September 2014: Congratulations, Amir, on passing your departmental Ph.D. defense!

4 September 2014: Congratulations to Amir on receiving a postdoc offer at Oxford!

4 September 2014: Congratulations to Dylan on receiving a postdoc offer at the University of Bristol!

4 September 2014: Belated congratulations to Lee, who is about to start a postdoc at the University of Vienna!

29 August 2014: Congratulations to Lee on successfully defending his Ph.D thesis!

2 June 2014: Kudos to Lee, James, and the rest of the team on the publication of our paper on using optical centroid measurements to achieve quantum superresolution!
(And thanks to Jonathan Matthews for the nice Physics Viewpoint about our work! also carried a report about the experiment.)

21 May 2014: Rockson's work is featured in

2 May 2014: Congratulations to Rockson and the team on the publication of our work on the onset of the effective mass!

18 March 2014: Science Daily and a few other sites are featuring stories about our work on the Superconducting QUAntum Light Emitting Diode.

12 March 2014: Congratulations to Alex et al. on surviving the war of attrition with Phys Rev referees, and on the publication of our proposal for generating entangled photons using the entanglement inherent in Cooper pairs.

Congratulations to Chao on joining the small army U of T Physics has sent to take over the Bank of Montreal!

5 Feb 2014: Congratulations to Emiliano and the rest on the publication of their PRL on "Ultrafast Stark-Induced Polaritonic Switches"!

3 Dec 2013: Congratulations to Chao and the whole gang on the publication of our paper on coherent control in optical lattices!

Follow this link for older group news & links

Group members

(For some old group photos, scroll down to Reza's photos, and for a more recent one courtesy of Big Brother, click here!
The pictures of our Chinese missile test are available here.)
The trick of being a quantum information scientist is to control a system without seeing what you're doing (since any observation would disturb the system.)
We are always looking for bright students and postdocs who are excited about probing the fundamental issues in quantum mechanics as well as investigating the possibilities for new technologies based on novel quantum effects.
A list of our present and past group members can be found below, with some links.


Our main interests are in fundamental quantum-mechanical phenomena,, and particularly quantum information processing and the control & characterization of the quantum states of systems ranging from laser-cooled atoms to individual photons. We are members of the Quantum Optics Group at U of T, of the Center for Quantum Information and Quantum Control (CQIQC), and of IOS, the new Institute for Optical Sciences. I am also a Fellow in the Quantum Information Processing programme of the Canadian Institute for Advanced Research and an affiliate member of the Perimeter Institute for Theoretical Physics.
Our projects are supported by NSERC, by QuantumWorks, by the Canadian Institute for Photonics Innovations, and by Photonics Research Ontario. We have also enjoyed support from DARPA, CFI, PREA, and ORDCF at various times.

Our experimental program is two-pronged, using both nonclassical two-photon interference and laser-cooled atoms to study issues such as quantum information & computation, decoherence and the quantum-classical boundary, tunneling times, weak measurement & retrodiction in quantum mechanics, and the control and characterisation of novel quantum states. For more information, scroll down to a text description of our present research topics and partial reverse-chronological list of publications, or click on one of the following pictures to access more details about some of our research areas.

Some sorted links to selections of our papers & talks:

Some general overviews of our research, quantum info, and problems in quantum measurement

Optical lattices (& quantum chaos, quantum control,...)

Entangled photons (& quantum information)

Bose-Einstein condensation (& atom tunneling)

Quantum measurement

Research projects

Specific projects of interest at the present time include:

For more information, feel free to download the papers and/or talks listed below, or to contact us directly.


(For an older publication list, with several links, go here)


How the Result of Counting One Photon Can Turn Out to Be a Value of 8, Matin Hallaji, Amir Feizpour, Greg Dmochowski, Josiah Sinclair, to appear (with a slighlty different title) in Nature Physics.

Shutting a new door on locality, A.M. Steinberg, Physics Today DOI:10.1063/PT.5.9076 (2016)

Simulating and Optimising Quantum Thermometry Using Single Photons , W.K. Tham, H. Ferretti, A.V. Sadashivan, and A.M. Steinberg, Sci. Rep. 6, 38822 (2016).

Beating Rayleigh's Curse by Imaging Using Phase Information, Weng Kian Tham, Hugo Ferretti, and Aephraim Steinberg, arXiv:1606.02666, to appear in Phys. Rev. Lett.

Interaction-assisted quantum tunneling of a Bose-Einstein condensate out of a single trapping well, Shreyas Potnis, Ramon Ramos, Kenji Maeda, Lincoln D. Carr, and Aephraim M. Steinberg, to appear in Phys. Rev. Lett.

Experimental Demonstration of the Effectiveness of Electromagnetically Induced Transparency for Enhancing Cross-Phase Modulation in the Short-Pulse Regime, Greg Dmochowski, Amir Feizpour, Matin Hallaji, Chao Zhuang, Alex Hayat, and Aephraim M. Steinberg, Phys. Rev. Lett. 116, 173002 (2016).

Experimental nonlocal and surreal Bohmian trajectories, Dylan Mahler, Lee Rozema, Kent Fisher, Lydia Vermeyden, Kevin Resch, Howard Wiseman, and Aephraim Steinberg, Science Advances 2, e1501466 (2016).

Short-pulse cross-phase modulation in an electromagnetically-induced-transparency medium, Amir Feizpour, Greg Dmochowski, and Aephraim Steinberg, Phys. Rev. A 93, 013843 (2016).

Observation of the nonlinear phase shift due to single post-selected photons, Amir Feizpour, Matin Hallaji, Greg Dmochowski, and Aephraim Steinberg, Nature Physics, DOI: 10.1038/nphys3433 (2015)

Characterizing an entangled-photon source with classical detectors and measurements, Lee Rozema, Chao Wang, Dylan Mahler, Alex Hayat, Aephraim Steinberg, John Sipe, and Marco Liscidini, Optica 2, 430 (2015).

A Note on Different Definitions of Momentum Disturbance, Lee Rozema, Dylan Mahler, Alex Hayat, and Aephraim Steinberg, posted 2013; actual publication in Phys Rev abandoned since despite positive reports from the referees, the paper was rejected on the grounds that the authors whose definitions of disturbance we were trying to clarify and contrast with those used in the paper of ours they criticized turned out (surprise surprise) not to like our definitions of disturbance... finally appeared in Quantum Studies: Mathematics and Foundations, 2015, 10.1007/s40509-014-0027-1

Enhanced coherence between condensates formed resonantly at different times, Alex Hayat, Christoph Lange, Lee Rozema, Rockson Chang, Shreyas Potnis, Henry van Driel, Aephraim Steinberg, Mark Steger, David Snoke, Loren Pfeiffer, and Kenneth West, Opt. Exp. 22, 30559 (2014)

Quantum Data Compression of a Qubit Ensemble, Lee Rozema, Dylan Mahler, Alex Hayat, Peter Turner, and Aephraim Steinberg, Phys. Rev. Lett. 113, 160504 (2014); chosen as an Editors' Suggestion and featured as a Focus in Physics 7, 106 (2014)

Experimental demonstration of a flexible time-domain quantum channel, Xingxing Xing, Amir Feizpour, Alex Hayat, and Aephraim Steinberg, Optics Express 22, 25128 (2014)

Scalable spatial superresolution using entangled photons, Lee Rozema(*), James Bateman(*), Dylan Mahler, Ryo Okamoto, Amir Feizpour, Alex Hayat, and Aephraim Steinberg, Phys. Rev. Lett. 112, 223602 (2014). [Selected as an Editors' Suggestion and for a Viewpoint in Physics.]
(*) These authors contributed equally to this work

On the Optimal Choice of Spin-Squeezed States for Detecting and Characterizing a Quantum Process, Lee Rozema, Dylan Mahler, Robin Blume-Kohout, and Aephraim Steinberg, Phys. Rev. X.4, 041025 (2014)

Observing the Onset of Effective Mass, Rockson Chang, Shreyas Potnis, Ramon Ramos, Chao Zhuang, Matin Hallaji, Alex Hayat, Federico Duque-Gomez, John Sipe, and Aephraim Steinberg, Phys. Rev. Lett. 112, 170404 (2014).

Ultra-Fast Stark-Induced Control of Polaritonic States, E. Cancellieri, A. Hayat, A.M. Steinberg, E. Giacobino, and A. Bramati, Phys. Rev. Lett. 112, 053601 (2014).

Sub-Rabi-cycle modulation of light-matter coupling, and onset of strong coupling, Christoph Lange, Alex Hayat, Lee A. Rozema, Rockson Chang, Shreyas Potnis, Henry M. van Driel, Aephraim M. Steinberg, Mark Steger, David W. Snoke, Loren N. Pfeiffer and Kenneth W. West, submitted 2013.

Cooper-pair based photon entanglement without isolated emitters, Alex Hayat, Hae-Young Kee, Kenneth S. Burch, and Aephraim M. Steinberg, submitted April 2013, accepted June 2013, sent back to referees based on unsolicited remarks sent to PRB editors by anonymous cranky individuals, and as of late October still in limbo thanks to this disgusting behaviour of the PRB editors (who even went so far as to retroactively doctor the automated "status inquiry" system to hide the fact that they sent us an acceptance letter on June 28th, not merely "miscellaneous communication"!) finally appeared in March 2014 as Phys. Rev. B {\bf 89}, 094508 (2014).

Enhanced Probing of Fermion Interaction Using Weak Value Amplification, Alex Hayat, Amir Feizpour, and Aephraim M. Steinberg, Phys. Rev. A 88, 062301 (2013).

In Praise of Weakness, Aephraim Steinberg, Amir Feizpour, Lee Rozema, Dylan Mahler, and Alex Hayat, Physics World March 2013, pp 35-40.

Adaptive quantum state tomography improves accuracy quadratically, Dylan Mahler, Lee Rozema, Ardavan Darabi, Chris Ferrie, Robin Blume-Kohout, and Aephraim Steinberg, Phys. Rev. Lett. 111, 183601 (2013).

Observation of Transient Momentum-Space Interference During Scattering of a Condensate from an Optical Barrier, Rockson Chang, Shreyas Potnis, Chris Ellenor, Mirco Siercke, Alex Hayat, and Aephraim Steinberg, Phys. Rev. A 88, 053634 (2013).

Coherent control of population transfer between vibrational states in an optical lattice via two-path quantum interference, Chao Zhuang, Christopher Paul, Xiaoxian Liu, Samansa Maneshi, Luciano Cruz, and Aephraim Steinberg, Phys. Rev. Lett. 111, 233002 (2013).

Multidimensional quantum information based on single-photon temporal wavepackets, Alex Hayat, Xingxing Xing, Amir Feizpour, and Aephraim M. Steinberg, Opt. Exp. 20, 29174 (2012).

Hybrid high-temperature superconductor-semiconductor tunnel diode, A. Hayat, P. Zareapour, S.Y.F. Zhao, A.Jain, I.G. Savelyev, M. Blumin, Z. Xu, A.Yang, G. D. Gu, H. E. Ruda, S. Jia, R. J. Cava, A. M. Steinberg, and K. S. Burch, Phys. Rev. X 2, 041019 (2012).

Identification of Decoherence-Free Subspaces Without Quantum Process Tomography, D.H. Mahler, L. Rozema, A. Darabi, and A.M. Steinberg, Phys. Rev. A 86. 052101 (2012)

Violation of Heisenberg's Measurement-Disturbance Relationship by Weak Measurements, Lee Rozema, Ardavan Darabi, Dylan Mahler, Alex Hayat, Yasaman Soudagar, and Aephraim Steinberg, Phys. Rev. Lett. 109, 100404 (2012); selected as an Editors' Suggestion and featured as a Synopsis in Physics.

Dynamic Stark Effect in Strongly Coupled Microcavity Exciton-Polaritons, Alex Hayat, Christoph Lange, Lee Rozema, Ardavan Darabi, Henry van Driel, Aephraim Steinberg, Bryan Nelsen, David Snoke, Loren Pfeiffer, and Kenneth West, Phys. Rev. Lett. 109, 033605 (2012).

Self-calibrating Quantum State Tomography, Agata M. Branczyk, Dylan H. Mahler, Lee A. Rozema, Ardavan Darabi, Aephraim M. Steinberg, and Daniel F. V. James, New J. Phys. 14, 085003 (2012).

Enhancing metrology sensitivity by weak measurements, Alex Hayat, Amir Feizpour, and Aephraim Steinberg, SPIE Newsroom 10.1117/2.1201112.004014 (2011).

Weak Measurement Amplification of Single-Photon Nonlinearity, Amir Feizpour, Xingxing Xing, and Aephraim M. Steinberg, Phys. Rev. Lett. 107, 133603 (2011).

Observing the Average Trajectories of Single Photons in a Two-Slit Interferometer, S. Kocsis, B. Braverman, S. Ravets, M.J. Stevens, R.P. Mirin, L.K. Shalm, and A.M. Steinberg, Science 332, 1170 (2011)

Experimental characterization of qutrits using SIC-POVMs, Z.E.D Medendorp, F.A. Torres-Ruiz, L.K. Shalm, G.N.M. Tabia, C.A. Fuchs, and A.M. Steinberg, Phys. Rev. A 83, 051801(R) (2011).

Coherence freeze in an optical lattice investigated via pump-probe spectroscopy, Samansa Maneshi, Chao Zhuang, Christopher R. Paul, Luciano S. Cruz, and Aephraim M. Steinberg, Phys. Rev. Lett. 105, 193001 (2010).

A reply to "Problems with modelling closed timelike curves as post-selected teleportation", Seth Lloyd, Lorenzo Maccone, Raul Garcia-Patron, Vittoria Giovanetti, Yutaka Shikano, Stefano Pirandola, Lee Rozema, Ardavan Darabi, Yasaman Soudagar, Lynden (Krister) Shalm, and Aephraim Steinberg (2011).

Closed timelike curves via post-selection: theory and experiment, Seth Lloyd, Lorenzo Maccone, Raul Garcia-Patron, Vittoria Giovannetti, Yutaka Shikano, Stefano Pirandola, Lee A. Rozema, Ardavan Darabi, Yasaman Soudagar, Lynden K. Shalm, and Aephraim M. Steinberg, Phys. Rev. Lett. 106, 040403 (2011).

Quantum measurement: A light touch, A.M. Steinberg, Nature 463, 890 (2010).

Improving Quantum State Estimation with Mutually Unbiased Bases, R.B.A. Adamson and A.M. Steinberg, Phys. Rev. Lett. 105, 030406 (2010).

Matchgate quantum computing and non-local process analysis, S. Ramelow, A. Fedrizzi, A.M. Steinberg, and A.G. White, New. J. Phys. 12, 083027 (2010).

Experimental joint weak measurement on a photon pair as a probe of Hardy's Paradox, J.S. Lundeen and A.M. Steinberg, Phys. Rev. Lett. 102, 020404 (2009).

Squeezing and over-squeezing of triphotons, L.K. Shalm, R.B.A. Adamson, and A.M. Steinberg, Nature 457, 67 (2009).

Bright filter-free source of indistinguishable photon pairs, F. Wolfgramm, X. Xing, A Cere, A. Predojevic, A.M. Steinberg, and M.W. Mitchell, Optics Express 16, 18145 (2008).

Detecting hidden differences via permutation symmetries, R.B.A. Adamson, P.S. Turner, M.W. Mitchell, and A.M. Steinberg, Phys. Rev. A 78, 033832 (2008).

Efficient vibrational-state coupling in an optical tilted-washboard potential via multiple spatial translations, Samansa Maneshi, Jalani F. Kanem, Chao Zhuang, Matt Partlow, and Aephraim M. Steinberg, Phys. Rev. A 77, 022303 (2008).

A double-slit 'which-way' experiment addressing the complementarity-uncertainty debate, R. Mir, J.S. Lundeen, M.W. Mitchell, A.M. Steinberg, H.M. Wiseman, and J.L. Garretson, New J. Phys. 9 (2007) 287

Preparation of pure and mixed polarization qubits and the direct measurement of figures of merit, R.B.A. Adamson, L.K. Shalm, and A.M. Steinberg, Phys. Rev. A 75, 012104 (2007).

Observation of high-order quantum resonances in the kicked rotor, J.F. Kanem, S. Maneshi, M. Partlow, M. Spanner, and A.M. Steinberg, Phys. Rev. Lett. 98, 083004 (2007).

Multiparticle State Tomography: Hidden Differences, R.B.A. Adamson, L.K. Shalm, M.W. Mitchell, and A.M. Steinberg, Phys. Rev. Lett. 98, 043601 (2007).

Optimal bounded-error strategies for projective measurements in non-orthogonal state discrimination, M.A.P. Touzel, R.B.A. Adamson, and A.M. Steinberg, Phys. Rev. A 76, 062314 (2007).

Phase Space Tomography of Classical and Nonclassical Vibrational States of Atoms in an Optical Lattice, J.F. Kanem, S. Maneshi, S.H. Myrskog, and A.M. Steinberg, J. Opt. B. 7, S705(2005).

Quantum Process Tomography on vibrational states of atoms in an optical lattice, S.H. Myrskog, J.K. Fox, M.W. Mitchell, and A.M. Steinberg, Phys. Rev. A 72, 013615 (2005)

Classical and Quantum Analysis of One-Dimensional Velocity Selection for Ultracold Atoms, J.K. Fox, H.A. Kim, S.R. Mishra, S.H. Myrskog, A.M. Jofre, L.R. Segal, J.B. Kim, and A.M. Steinberg, J. Opt. B. 7, 240 (2005).

Quantum nonlocality obtained from local states by entanglement purification, P. Walther, K.J. Resch, C. Brukner, A.M. Steinberg, J.-W. Pan, and A. Zeilinger, Phys. Rev. Lett. 94, 040504 (2005)

Optical realization of optimal unambiguous discrimination for pure and mixed quantum states, M. Mohseni, A.M. Steinberg, and J. Bergou, Phys. Rev. Lett. 93, 200403 (2004)

Super-resolving phase measurements with a multi-photon entangled state, M.W. Mitchell, J.S. Lundeen, and A.M. Steinberg, Nature 429, 161 (2004).

Extracting joint weak values with local, single-particle measurements, K.J. Resch and A.M. Steinberg, Phys. Rev. Lett. 92,130402 (2004).

Experimental Realization of the Quantum Box Problem, K.J. Resch, J.S. Lundeen, A.M. Steinberg, Phys. Lett. A 324, 125 (2004).

Photon-exchange effects on photon-pair transmission, K.J. Resch, G.G. Lapaire, J.S. Lundeen, J.E. Sipe, A.M. Steinberg, Phys. Rev. A 69, 063814 (2004).

Clear message for causality, A.M. Steinberg, Physics World (Dec. 2003).

Experimental Characterization of 1-D Velocity Selection, S.H. Myrskog, J.K. Fox, L.R. Segal, A.M. Steinberg, A.M. Jofre, and S.R. Mishra, J. Kor. Phys. Soc 47, 6 (2005).

Diagnosis, prescription and prognosis of a Bell-state filter by quantum process tomography, M.W. Mitchell, C.W. Ellenor, S. Schneider, and A.M. Steinberg, Phys. Rev. Lett. 91, 120402 (2003).

Experimental application of decoherence-free subspaces in a optical quantum computing algorithm, M. Mohseni, J.S. Lundeen, K.J. Resch, and A.M. Steinberg, Phys. Rev. Lett. 91, 187903 (2003).

Speakable and Unspeakable, Past and Future, A.M. Steinberg, in SCIENCE AND ULTIMATE REALITY: Quantum Theory, Cosmology and Complexity, ed. John D. Barrow, Paul C.W. Davies, and Charles L. Harper, Jr., Cambridge University Press, 2003.

Practical creation and detection of polarization Bell states using parametric down-conversion, K.J. Resch, J.S. Lundeen, and A.M. Steinberg, in The Physics of Communication, Proceedings of the XXII Solvay Conference on Physics, Antoniou, Sadovnichy, and Walther eds., World Scientific (2003), pp 437-451.

A conditional-phase switch at the single-photon level, K.J. Resch, J.S. Lundeen, and A.M. Steinberg, Phys. Rev. Lett. 89, 037904 (2002).

Experimental issues in quantum-mechanical time measurement, A.M. Steinberg, in Time in Quantum Mechanics, edited by J.G. Muga et al. (Springer-Verlag, 2002), pp. 305-325

Quantum state preparation and conditional coherence, K.J. Resch, J.S. Lundeen, and A.M. Steinberg, Phys. Rev. Lett. 88, 113601 (2002).

Electromagnetically induced opacity for photon pairs, K.J. Resch, J.S. Lundeen, and A.M. Steinberg, J. Mod. Opt. 49, 487 (2002).

Nonlinear optics with less than one photon, K.J. Resch, J.S. Lundeen, and A.M. Steinberg, Phys. Rev. Lett 87, 123603 (2001).

Comment on 'Manipulating the frequency entangled states by an acoustic-optical modulator,' K.J. Resch, S.H. Myrskog, J.S. Lundeen, and A.M. Steinberg, Phys. Rev. A 64, 056101 (2001).

Experimental observation of nonclassical effects on single-photon detection rates, K.J. Resch, J.S. Lundeen, and A.M. Steinberg, Phys. Rev. A 63, 020102 (2000).

Total reflection does not occur in negative time, K.J. Resch, J.S. Lundeen, and A.M. Steinberg, IEEE J. Quant. Electr. 37, 794 (2001).

No thing goes faster than light, A.M. Steinberg, Physics World 13, 21 (2000).

Modified "delta kick cooling" using magnetic field gradients, S.H. Myrskog, J.K. Fox, H.S. Moon, J.B. Kim, and A.M. Steinberg, Phys. Rev. A 61, 053412/1-6 (2000).

Nanokelvin of the North, S.H. Myrskog, J.K. Fox, and A.M. Steinberg, Physics in Canada 55, 149 (7-8/99).

On energy transfer by detection of a tunneling atom, A. M. Steinberg, Journal of the Korean Physical Society 35 (3), 122 (1999).

`` An atom optics experiment to investigate faster-than-light tunneling,'' A.M. Steinberg, S. Myrskog, Han Seb Moon, Hyun Ah Kim, Jalani Fox, and Jung Bog Kim, Ann. Phys. (Leipzig) 7, 593 (1998).

`` Can a falling tree make a noise in two forests at the same time?'', A. M. Steinberg, in Causality and Locality in Modern Physics, S. Jeffers, G. Hunter, and J.-P. Vigier, eds., Kluwer Academic Publishers (Dordrecht: 1997), p. 431.

`` Squeezing with cold atoms", A. Lambrecht, T. Coudreau, A.M. Steinberg, and E. Giacobino, Europhysics Letters, vol. 36, (no. 2): 93-98, 10 October 1996.

``Quantum non-locality in two-photon experiments at Berkeley", R.Y. Chiao, P.G. Kwiat, and A.M. Steinberg, Quantum and Semiclassical Optics, vol. 7, (no. 3): 259-78, June (1995).

``Conditional probabilities in quantum theory and the tunneling-time controversy", A.M. Steinberg, Physical Review A, vol. 52, (no. 1): 32-42, July (1995).

``How much time does a tunneling particle spend in the barrier region?", A.M. Steinberg, Physical Review Letters, vol. 74, (no. 13): 2405-9, March (1995).

``Measurement of the single-photon tunneling time", A.M. Steinberg, P.G. Kwiat, and R.Y. Chiao, Phys. Rev. Lett., vol. 71, (no. 5): 708-11, August (1993).

Tunneling Times and Superluminality, R. Y. Chiao and A. M. Steinberg, in Progress in Optics vol. XXXVII, Emil Wolf ed., Elsevier (Amsterdam: 1997), pp. 347-406.

Quantum Optical Tests of the Foundations of Physics, A.M. Steinberg, R.Y. Chiao, and P.G. Kwiat, in the American Insitute of Physics Atomic, Molecular, and Optical Physics Handbook, edited by G.W.F. Drake, AIP Press, 1996.

Optical tests of quantum mechanics, R.Y. Chiao, P.G. Kwiat, and A.M. Steinberg, in Advances in Atomic, Molecular, and Optical Physics, vol. 34, B. Bederson and H. Walther eds, Academic Press, 1994.

`` Faster Than Light?", R.Y. Chiao, P.G. Kwiat, and A.M. Steinberg, Scientific American, vol. 269, (no. 2): 52-60, August (1993).

What does 'Gedankenexperiment' mean?

Babar et les variables cachées


How to Count One Photon and Get a Result of 8, invited lecture at the Technion, 2016

Weak measurement, uncertainty relationships, and tradeoffs in experimental quantum measurements, slides and video of a presentation given at the celebration of Yakir Aharonov's 80th birthday at Chapman university, August 2012.

God's Dice: From Einstein to the Internet is a talk I gave for the PASU and Engineering Science students on Nov 24, 2009, updated from an earlier talk at the Ontario Science Centre in celebration of the Einsteinjahr. It goes from wave-particle duality and the Bohr-Einstein debates through the EPR Paradox and Bell's Inequalities to a layman's introduction to quantum cryptography, computation, and teleportation.

Testing a new way of sharing files...

Thinking Inside the Box: Weakly Measuring Postselected Ensembles, The Clock and the Quantum, Sep 2008, at PI's site as Flash Presentation.

Tomography on the Sphere, Krister's talk at the QUEST workshop, August 2008 (multimedia format at PI's site)

Improving Quantum State Tomography with Mutually Unbiased Bases, Rob's talk at the QUEST workshop, August 2008 (multimedia format at PI's site)

Measuring Quantum States in the Presence of Fundamental Symmetries, invited talk at QCMC (Calgary, August 2008).

Quantum states of light and quantum interference, first of two talks at the Michigan Quantum Summer School (June 2008); or mp4 video.

Quantum measurement and quantum information with photons, second of two talks at the Michigan Quantum Summer School (June 2008); or mp4 video.

Decoherence and Control of Vibrational States of Atoms in an Optical Lattice

A recent overview of our work on controlling and measuring atoms and photons

A poster describing some of the major goals of our BEC experiment, as of February 2007

Chris's talk about our BEC experiment

Samansa's talk about control of optical lattices

Matt's talk about our observation of quantum resonances in an optical lattice

Manipulating and Measuring the Quantum State of Photons and Atoms, invited talk at QUEST workshop 2005.

Our latest progress towards BEC of 87Rb, and planned experiments

Le photon dans tous ses états, séminaire du Collège de France, mai 2004.

Small-scale quantum information processing with linear optics, presentation by Masoud Mohseni at Quantum Physics of Nature meeting, Vienna, May 2005.

Expériences de tomographie et d'échos dans des réseaux optiques, séminaire à l'Institut d'Optique à Orsay, mai 2004.

Annual report on our tailored quantum error correction project, May 2004.

Recent experiments on weak measurement and quantum state construction, Quantum Theory seminar, Tel-Aviv University, April 2004.

Series of lectures on Experimental Issues in Quantum Measurement, Vienna, Fall 2003.

Nonlinear optics at the quantum level and quantum information in optical systems.

Quantum Process Tomography in an Optical Lattice, Stefan's talk at DAMOP 2003.

Tunneling-Induced Coherence in Optical Lattices, Samansa's poster for the 2003 Cross-Border Workshop.

Optical implementation of the Quantum Box Problem, QELS 03 talk by K. Resch, J. Lundeen, and A. Steinberg.

An Experimental Implementation of Hardy's Paradox, QELS 03 talk by J.S. Lundeen, K.J. Resch, and A.M. Steinberg.

Quantum algorithms in the presence of decoherence: optical experiments, QELS 03 talk by M. Mohseni, J. Lundeen, K. Resch, and A. Steinberg.

Playing Games With the Information in Atoms and Photons, one version of a colloquium I've been giving in 2003 describing a number of our ongoing projects.

Quantum Information With Photons and Atoms, talk by A.M. Steinberg at the Physics of Quantum Electronics conference (2003).

Motional Quantum State Tomography on Atoms in an Optical Lattice, poster by S.H. Myrskog, J.K. Fox, and A.M. Steinberg (2002).

Optical Implementation of the Deutsch-Jozsa Algorithm in the Presence of Noise, poster by M. Mohsen, J.S. Lundeen, K.J. Resch, and A.M. Steinberg (2002) (also available in pdf format).

Amplification of Superluminality,presentation at ITP Mini-Workshop on Quantum Optics (2002) by A.M. Steinberg.

Efficient 1-D velocity selection in laser-cooled atom clouds, S.H. Myrskog, J.K. Fox, A.M. Jofre, L.R. Segal, S.R. Mishra, and A.M. Steinberg, at the 8th Rochester Conference on Coherence and Quantum Optics, June 2001.

Kevin's talk on ``Coherence conditioned on a single photon'' at the International Conference on Squeezed States and Uncertainty Relations, Boston, 2001.

Experiments with Entangled Photons, lecture by A.M. Steinberg at the May 2001 Fields Institute Summer School in Quantum Information Processing.

Transparencies for Jeff's talk on Nonlinear Optics With Less Than One Photon at the Snowbird Winter Conference on Quantum Electronics, January 2001.

We presented a poster at the Euroschool on Bose Condensation and Atom Optics in July, 2000 on our velocity-selection work and plans to observe atomic tunneling.

We presented a poster at DAMOP 2000 on an ongoing experiment to test 100% Reflection in Less Than No Time at All.

We presented a poster at the Gordon Conference on Dynamics of Simple Systems in the summer of 1999, discussing Velocity-Selection of Ultracold Atoms .

We presented two posters at the 16th International Conference on Atomic Physics in August, 1998. One was entitled Ultra-Cold atoms for investigations into atomic tunneling, and the other was Quantum Interference with Femtosecond Photon Pair Pulses.

Research Associates, Postdocs and Visitors

As of May 2016, Aharon Brodutch has joined us as a CQIQC Prize Postdoctoral Fellow.

As of Jan 2017, Kent Bonsma-Fisher has joined us as an NSERC postdoctoral fellow.

Alan Stummer (Research Laboratory Technologist)
(Postdoctoral opportunities available)

Graduate Students

Ramon Ramos: Bose-Einstein condensation and tunneling times

Hugo Ferretti: Entangled photons and quantum metrology

Josiah Sinclair: Quantum light-matter interfaces and Rydberg blockade

David Spierings: BEC

Edwin Tham: Quantum channels, quantum thermometry, and quantum-inspired imaging

Alex Bruening: LMI

Shaun Pepper: LMI

Isabelle Racicot: BEC

Arthur Pang: entangled photons and Bohm trajectories

Noah Lupu-Gladstein: entangled photons and the pigeonhole principle

Undergraduate Students

Sepehr Ebadi is back working with us in 2017.
Jamie Woodbury worked with us in the winter of 2013... and then I think I didn't update this part of the web page for a few years...
James Bateman has been working with us for 2012-2013.
Aysha Abdel-Aziz has been working with us for 2012-2012.
(For undergraduate research opportunities, see

Some of our collaborators (past, present, and future)

Daniel James
John Sipe
Paul Brumer
Joseph Thywissen
Morgan Mitchell
Nicolas Godbout
Allan Griffin
Paul Kwiat
Andrew White
Ray Chiao
Peter Turner
Sasha Sergienko
J. Gonzalo Muga
Janos Bergou
Mark Hillery
Daniel Lidar
Alain Aspect
Raymond Laflamme
Sergei Kulik
Maria Chekhova
Misha Ivanov
John Behr
Ivan Deutsch
Poul Jessen
Raymond Laflamme
Terry Rudolph
Rob Spekkens
Anton Zeilinger
Rich Mirin

Former group members

Former grad students:

Matin Hallaji has joined the hordes of physicists at ScotiaBank, after finishing his Ph.D. in 2016.

Greg Dmochowski completed his Ph.D. in 2015.

Shreyas Potnis is a postdoc with Amar Vutha's group in Toronto.

Amir Feizpour is a postdoc at Oxford.

Dylan Mahler is a postdoc at Bristol.

Lee Rozema is a postdoc at Vienna.

Rockson Chang is a postdoc at the Institut d'Optique, Palaiseau.

Xingxing Xing, after completing his PhD with us, has started a quantum cryptography company.

Chao Zhuang moved into finance after completing his PhD with us.

Paul Godin did his M.Sc. with us in 2011-2012.

Yasaman Soudagar: after collaborating with us during her Ph.D. with Prof. Nicolas Godbout of the Ecole Polytechnique, Yasaman is now an NSERC Industrial Postdoc.

Chris Ellenor: Bose-Einstein condensation and interactions with dipole barrier
(Chris is now a postdoc at Stanford working on the development of novel MRI systems)
Mirco Siercke: dissertation copy-editing (Mirco is now a postdoc with Rainder Dumke in Singapore)
Samansa Maneshi: Tomography and control in optical lattices (Samansa is now a postdoc with Dwayne Miller in Hamburg)
Lynden (Krister) Shalm is now a postdoc with Rich Mirin's group at NIST-Boulder, after completing a stint as a CIFAR Junior Academy Fellow working with Thomas Jennewein and our own Kevin Resch at the Institute for Quantum Computing in Waterloo.
Zhenfu Zhang has now moved to Claudiu Gradinaru's biophysics group.
Sacha Kocsis, who did his M.Sc. with us, is now working on a Ph.D. with Geoff Pryde at Griffith University.
Alexandra Mech spent a 2-week "secondment" visiting us from the group of Anton Zeilinger in Vienna.

Chris Paul is now an official mountain-biking bum.
Zach Medendorp was torn between teacher's college and medical school the last time I spoke to him.
I've lost touch with Adam Weir.
Florian Wolfgramm, collaborator and sometime visitor, is still a student of Morgan Mitchell at ICFO, Barcelona.
Rob Adamson is now a research assistant professor at Dalhousie (Ph.D. 2008).
Jalani Fox Kanem (Ph.D. 2006, and then a postdoc with Ed Hinds, Imperial College, London), went to ScotiaBank, where he is toiling away to complete the destruction of the global financial markets..
Jeff Lundeen (Ph.D. 2006), after a postdoc with Ian Walmsley, Oxford, and a short stay with Morgan Mitchell's group at ICFO, Barcelona, is now a Research Associate at NRC, working on Quantum Information and Metrology with Photons..
Ana Jofre (Ph.D. 2004; then a postdoc at NIST); paid as an Asst. Prof. at UNC Charlotte since Fall '07), but really an artist.
Stefan Myrskog (Ph.D. 2003; pdf with Joseph Thywissen, and then with Ted Sargent and Peter Smith in ECE) is now Chief Scientist at Morgan Solar.
Kevin Resch (1997-PhD 2002); did a postdoc with Anton Zeilinger, and one with Andrew White; now an Assistant Professor at IQC and the Physics Department at Waterloo)
Jason Ng (M.Sc. 2008)
Xiaoxian Liu: Sideband engineering and adiabatic control methods in an optical lattice (M.Sc. 2007)
Masoud Mohseni (M.Sc. 2002; Ph.D. with Daniel Lidar; now a postdoc in the Aspuru-Guzik group at Harvard)
Brock Wilson (now at D-Wave Systems).
Fan Wang (M.Sc. 2005), now working with Young-June Kim
Sal Maone
Reza Mir (M.Sc. 2003)
Lauren Segal (1999-2000); completed her M.Sc. and is now a mezzo-soprano with the Canadian Opera Company.
Chris Dimas (1998-9); now an optical design engineer at EFOS (EXFO)

Other former group members:

Alex Hayat, Banting and CQIQC and CIFAR postdoc with us from 2011-2014, is now a professor at the Technion.
Kelsey Allen worked with us in the summer of 2012.
Zach Vernon worked with us in the summer of 2012.
Lee Liu did his Eng Sci senior thesis with us in 2011-2012.
Benoit Cyrenne spent the summer of 2011 working with us.
Julian Schmidt and
Patrik Rath spent 2010-2011 as exchange students in our lab; both are now finishing their studies in Germany.
Assaf Bar-Natan, from the Abelard School, also volunteered in our lab during 2010-2011; he is now a student at the Hebrew University of Jerusalem.
Aleksander Kubica worked with us for the summer of 2010 on a CQIQC fellowship; he is now a student at Cal Tech.
Phil Russ worked with us for the summer of 2010 on an NSERC fellowship.
Timur Rvachov worked with us for the summer of 2010 on an NSERC fellowship; he is now a student at MIT.
Sylvain Ravets (stagiaire from ENS-Cachan)
Anselm Schultes (exchange student from Uni. Würzburg)
Boris Braverman worked with us on and off through 2010, and is now a grad student at MIT.
Luciano Cruz is now an assistant professor at UABC in Sao Paulo.
Fabian Torres, visiting "predoc" from Carlos Saavedra's group at the Center for Quantum Optics and Quantum Information, Concepcion, is now at the Universidad de la Frontera in Temuco, Chile.
Nick Chisholm is now a physics grad student with Misha Lukin at Harvard.
Eva Markowski is now a student at Harvard Law
Amanda O'Halloran
Ardavan Darabi did some excellent work with us as a Ph.D. student before moving to the UK to become a financier, art thief, and international man of mystery.
Ahmed al-Mehairi
Nick Miladinovic
Morgan Mitchell (postdoc 2002-2004; now a Research Assistant Professor at the Institut de Ciències Fotòniques in Barcelona)
Marcelo Martinelli (pdf 2003; now an Asst. Prof. at University of Sao Paulo)
Matt Partlow (postdoctoral fellow)
An-Ning Zhang went on to do a postdoc with Alex Lvovsky at IQIS and the Department of Physics & Astronomy, Calgary.
Nan Yang
Michael Sitwell
Curtis Leung
Arthur Chang
Rebecca Nie
Eugen Friesen
Christian Rewitz
Max Touzel
Sabrina Liao
Shannon Wang
Ray Gao
Alexander Thobe
Jan Hennneberger, Universität Würzburg (visiting 2004-5)
Enguerrand Menard, ENS-Lyon (visiting 2005)
Alpha Gaëtan, Univ. Orsay (visiting 2005)
Karen Saucke (2003)
Guillaume Foucaud (summer 2002); continuing at Ecole Superieure d'Optique, Orsay.
Jai Grover (summer 2001); completed his B.Sc. at Toronto, and is now a Ph.D. student at Cambridge.
David Glenn (2000-2001); completed M.Sc. at U. of T. with Prof. Daniel Lidar in Fall '02, and now completing his Ph.D. at Yale University.
Satya Ram Mishra (2000-2001); now back at the Centre for Advanced Technology, Indore, India.
David Caplan (summer 2000); completed B.Sc. UBC and now a graduate student at University of Illinois.
Laurent Lombard (summer 2000); back at ESO - Orsay.
Laure Wawrezinieck (summer 2000); back at ENS-Cachan.
Naomi Ginsberg (1999-2000); currently finishing her Ph.D. with Lene Hau at Harvard -- see Physics News Update and Nature News&Views for stories about her work; moving on to a postdoctoral position in the Fleming group at Berkeley, where she now leads her own research group in the Department of Chemistry.
Phillip Hadley (1998-2000); after working with Paul Kwiat at Los Alamos National Labs, and as a metrology engineer at CVI Laser, completed his undergraduate degree at U of T and was about to begin an internship at LAM Research until he got stopped at the U.S. border.
Sarah Karram (summer 1999; at Trent University)
Magali Davenet (summer 1999; at the Ecole Superieure d'Optique, Orsay)
Kevin Lee (summer 1998)
Jung Bog Kim (1997-8; back at the Korea National Univ. of Education)
Han Seb Moon (1997; KNUE)
Hyun Ah Kim (1997-8; KNUE)
Jason McKeever (1997-8; Ph.D. at Cal Tech -- see Physics News Update for story on his work -- then did a postdoc with Christophe Salomon before returning to Toronto as a pdf with Joseph Thywissen)
Roy Wang (summer 1997; moved to JDS Uniphase; spent some time attempting to sell his body after that didn't last; moved into sales engineering at Human Solutions after that didn't last either)
Navin Bhat (jointly with Prof. Paul Brumer during summer 1997; now a Ph.D. student with Prof. John Sipe )
Maryna Savchenko

Click on photo for access to our last group-photo gallery, courtesy of Reza Mir.

Or click here for the anonymous, candid group photo.

Click above to see a photo of our trapped atoms.

For more information and assorted links, see

Aephraim Steinberg's home page.

This site is maintained by inertia, but comments may be addressed to Aephraim M. Steinberg.