PUBLICATIONS BY DISCIPLINE
PHOTON LOCALIZATION AND PHOTONIC BAND GAP MATERIALS
Since the invention of the laser, the field
of photonics has progressed through the development of engineered materials
which mold the flow of light. Photonic
band gap (PBG) materials are a new class of dielectrics which are the
photonic analogues of semiconductors. They represent a new frontier
in quantum optics and offer many new technological application. Unlike
semiconductors which facilitate the coherent propagation of electrons,
PBG materials facilitate the coherent localization
of photons. Our research suggests that PBG materials exhibit
fundamentally new physics such as photon-atom bound states, lasing
without a cavity mode, quantum optical spin-glass states of impurity atomic
dipoles, and optical gap solitons. Applications include zero-threshold
micro-lasers with high modulation speed and low threshold optical
switches and all-optical transistors for optical telecommunications
and high speed optical computers.
Our current research is aimed at developing a theoretical understanding
of these novel materials. Specific calculations include N-atom collective
spontaneous emission and laser activity. Light emission properties of photonic
band gap materials differ dramatically from conventional lasers. The most
fundamental novelty of these materials comes from the fact that when
an atom or molecule, placed within the material, has an electronic transition
which lies within the photonic band gap, spontaneous emission of light
from the atom is inhibited. Instead, the photon
forms a bound state to the atom! This has profound implications
for laser activity. Spontaneous emission is the dominant loss mechanism
in a conventional laser. In a PBG, lasing can occur with zero pumping threshold.
Lasing can also occur without mirrors and without a cavity mode since each
atom creates its own localized photon mode. This suggests that large arrays
of nearly lossless microlasers for all-optical circuits can be fabricated
with PBG materials.
Near a photonic band edge, the photon density of states exhibits singularities
which cause collective light
emission to take place at a much faster rate than in ordinary vacuum.
. We have shown that this rate is proportional to the square of the number
N of atoms rather than simply N itself as it would be in conventional systems.
demonstrates that microlasers operating
near a photonic band edge will exhibit ultrafast modulation and switching
speeds for application in high speed data transfer and computing.
Applications such as telecommunications, data transfer, and computing
will be greatly enhanced through all-optical processing in which
bits of information, encoded in the form of a photon number distribution,
can be transmitted and processed without conversion to and from electrical
signals. In this manner, the information contained in an entire encyclopedia
can be transmitted over a fibre optic phone line in a matter of seconds.
This relies on the development of ultra-low noise coherent light sources.
We are evaluating the quantum statistics of photons produced by laser emission
in a PBG material to evaluate the extent of signal noise reduction referred
to as photon-antibunching and squeezing. These are crucial to lowering
the bit error rate in optical telecommunication networks. In a PBG material
the drastic reduction of spontaneous emission as well as the reduction
of propagative pathways for photons, facilitates the realization of very
low quantum noise.
A PBG material doped with impurity atoms also exhibits novel
nonlinear optical properties due to the resonance dipole-dipole
interaction (RDDI) between atoms. Our current calculations show that under
pumping by a weak external laser field, this system acts as a nearly lossless,
nonlinear material which exhibits optical
bistability. We are currently investigating the possibility of
using this system as a very low threshold, ultra-high speed optical switch.
This low threshold nonlinearity is a consequence of a new equilibrium
state of photons and atoms in a PBG which we refer to as a quantum optical
spin-glass state. In this state, the atomic dipoles exhibit a spontaneous,
frozen-in, random polarization. The light associated with this state is
intermediate between coherent light from a conventional laser and chaotic
light from an ordinary light bulb. We refer to this state as a Bose-glass
state of photons .
The photonic band gap is a frequency interval over which the linear
electromagnetic propagation effects have literally been turned off. However,
the PBG exhibits a rich variety of nonlinear optical propagation phenomena.
These include classical gap solitons
gap solitons . These solitons may be important in the transmission
of information through the otherwise impenetrable PBG.
The PBG material provides dopant atoms with a high degree of protection
from damping effects of spontaneous emission and dipole dephasing. In this
case the two-level atom may act as a two-level quantum mechanical register
or single photon logic gate for all optical quantum computing .
We are currently studying two models for quantum computation within PBG
materials. The first involves an atom which is laser-cooled in the void
regions of a PBG material. In this case a polarized photon (flying qubit)
with frequency just outside of the gap excites a protected atomic level
inside the gap (stationary qubit) by resonant coupling to a third atomic
level just outside the gap. The second and third atomic levels are coupled
by an external laser field which drives a two-photon transition. This
single atom acts as a phase sensitive quantum memory device. The
resulting qubit is robust to decoherence
effects provided that the Rabi frequency of the coherent laser
field exceeds the rate of dephasing interactions. In effect, coherence
is externally imposed on the system.
Sajeev John, H. Sompolinsky and Michael J. Stephen, Phys. Rev. B 27,
5592 (1983) "Localization in a Disordered Elastic Medium Near Two dimensions". ABSTRACT PDF
*Sajeev John and Michael J. Stephen, Phys. Rev. B 28, 6358 (1983)
"Wave Propagation and Localization in a Long Range Correlated Random Potential". ABSTRACT PDF
Sajeev John, Phys. Rev. Lett. 53, 2169 (1984) "Electromagnetic
Absorption in a Disordered Medium near a Photon Mobility Edge". ABSTRACT PDF
S. John, Phys. Rev. Lett. 58, 2486 (1987) "Strong Localization of
Photons in Certain Disordered Dielectric Superlattices". ABSTRACT
S. John and R. Rangarajan, Phys. Rev. B38, 10101 (1988) "Optimal
Structures for Classical Wave Localization: An Alternative to the Ioffe-Regel
S. John and J. Wang, Phys. Rev. Lett. 64, 2418 (1990) "Quantum Electrodynamics
Near a Photonic Band Gap: Photon Bound States and Dressed Atoms". ABSTRACT
S. John, Physics Today, May 1991 (cover story) and
page 32 "Localization of Light".
Sajeev John and Jian Wang, Phys. Rev. B 43, 12, 772 (1991) "Quantum
Optics of Localized Light in a Photonic Bandgap". ABSTRACT
S. John and N. Akozbek, Phys. Rev. Lett. 71, 1168 (1993) "Nonlinear
Optical Solitary Waves in a Photonic Band Gap". ABSTRACT
S. John and T. Quang, Phys. Rev. A50, 1764 (1994) "Spontaneous Emission
near the Edge of a Photonic Band Gap". ABSTRACT
S. John and T. Quang, Phys. Rev. Lett. 74, 3419 (1995) "Localization
of Superradiance near a Photonic Band Gap". ABSTRACT
Sajeev John and Tran Quang, Physical Review A 52, 4083 (1995) "Photon
Hopping Conduction and Collectively Induced Transparency in a Photonic
S. John and T. Quang, Phys. Rev. Lett. 76, 1320 (1996) "Quantum
Optical Spin-Glass State of Impurity Two-Level Atoms in a Photonic Band
S. John and T. Quang, Phys. Rev. Lett. 76, 2484 (1996) "Resonant
Nonlinear Dielectric Response in a Photonic Band Gap Material". ABSTRACT
S. John and T. Quang, Phys. Rev. A 54, 4479 (1996) "Optical Bistability
and Phase Transitions in a Doped Photonic Band Gap Material". ABSTRACT
Sajeev John and Tran Quang, Physical Review Letters, 78, 1888 (1997)
"Collective Switching and Inversion without Fluctuation of Two-Level Atoms
in Confined Photonic Systems''. ABSTRACT
Sajeev John and Valery Rupasov, Physical Review Letters 79, 821
(1997) "Multi-photon Localization and Propagating Quantum Gap Solitons
in a Frequency Gap Medium". ABSTRACT
Tran Quang, M. Woldeyohannes, Sajeev John and G.S. Agarwal, Physical Review
Letters 79, 5238 (1997) "Coherent Control of Spontaneous Emission
Near a Photonic Band Edge: A Single-Atom Optical Memory Device". ABSTRACT
Tran Quang and Sajeev John, Physical Review A, 56, 4273 (1997) "Resonance
Fluorescence near a Photonic Band Edge: Dressed-State Monte Carlo Wave-function
Sajeev John, Nature, 390, 661 (1997) "Frozen Light". ABSTRACT
Neset Akozbek and Sajeev John, Physical Review E 57, 2287 (1998)
"Optical Solitary Waves in Two- and Three-Dimensional Nonlinear Photonic
Band-Gap Structures". ABSTRACT
Neset Akozbek and Sajeev John, Physical Review E 58, 3876 (1998)
"Self-Induced Transparency Solitary Waves in a Doped Photonic Band Gap
Kurt Busch and Sajeev John, Physical Review E 58, 3896 (1998)
"Photonic Band Gap Formation in Certain Self-Organizing Systems". ABSTRACT
Nipun Vats and Sajeev John, Physical Review A 58, 4168-4185 (1998)
"Non-Markovian Quantum Fluctuations and Superradiance Near a Photonic Band
Sajeev John and V. Rupasov, Europhysics Letters 46 (3), 326 (1999)
"Quantum Self-Induced Transparency in Frequency Gap Media". ABSTRACT PDF
Mesfin Woldeyohannes and Sajeev John, Physical Review
A60(6), 5046-5068 (1999) "Coherent control of spontaneous emission near a photonic band edge: A
qubit for quantum computation". ABSTRACT
"Large-scale synthesis of a silicon photonic crystal with a complete three-dimensional bandgap near 1.5 micrometres", Alvaro Blanco, Emmanuel Chomski, Serguei Grabtchak; Marta Ibisate, Sajeev John, Stephen W. Leonard, Cefe Lopez, Francisco Meseguer,
Hernan Miguez, Jessica P. Mondia, Geoffrey A. Ozin, Ovidiu Toader and Henry M. van Driel,
Nature 405 (6785), 437-440 (2000).
- "Attenuation of Optical Transmission within the bandgap of thin two-dimensional macroporous silicon photonic crystals", S. W. Leonard, H. van Driel, K. Busch, S. John et al., Applied Physics Letters 75, 3063 (1999). ABSTRACT PDF POSTSCRIPT
- "Tunable two-dimensional photonic crystals using liquid-crystal infiltration", S. W. Leonard, J. P. Mondia, H. van Driel, O. Toader, S. John et al., Physical Review B, Phys. Rev. B 61, R2389 (2000). ABSTRACT PDF POSTSCRIPT
- "Resonance Raman Scattering in Dispersive Media and Photonic Band Gaps", M. Woldeyohannes, Sajeev John and V. Rupasov, Physical Review A 63, 13814 (2001). ABSTRACT PDF POSTSCRIPT
- "Radiating Dipoles in Photonic Crystals", K. Busch, N. Vats, Sajeev John and B. Sanders, Physical Review E 62, 4251 (2000). ABSTRACT PDF POSTSCRIPT
- "Optical Trapping, Field Enhancement, and Laser Cooling in Photonic Crystals", Ovidiu Toader, Sajeev John and K. Busch, Optics Express vol.8, no. 3, pg 271- (2001). ABSTRACT PDF
- "Single Atom Switching and NonMarkovian Dynamics in a Coloured Vacuum", M. Florescu and Sajeev John, Physical Review A 64, 033801 (2001). ABSTRACT PDF POSTSCRIPT
- "Proposed Square
Spiral Microfabrication Architecture for Large Three-Dimensional Photonic Band
Crystals", Ovidiu Toader and Sajeev John, Science vol. 292, 1133 (2001). ABSTRACT PDF
- "Photonic Band Gap Materials: Towards an All-Optical Micro-Transistor", Sajeev John and Marian Florescu, Journal of Optics A: Pure and Applied Optics 3, S103 (2001). ABSTRACT PDF
- "Photonic Bandgap Engineering in Germanium Inverse Opals by Chemical Vapor Deposition", H. Miguez, E. Chomski, F. Garcia-Santamaria, M. Ibisate, S. John, C. Lopez, F. Meseguer,
J. P. Mondia, G. A. Ozin, O. Toader, H. M. van Driel, Advanced Materials 13, No.21, 1634 (2001).
- "Fabrication of Tetragonal Square Spiral Photonic Crystals", Scott Kennedy, Michael Brett, Ovidiu Toader, and Sajeev John, Nano Letters Vol. 2, No. 1, 59, (2002). ABSTRACT PDF
- "Theory of Fluorescence in Photonic Crystals", Nipun Vats, K. Busch, Sajeev John, Physical Review A 65, 043808 (2002). ABSTRACT PDF POSTSCRIPT
- "Enhancement of two-photon emission in photonic crystals ", Przemyslaw Markowicz, Christopher Friend, Yuzhen Shen, Jacek Swiatkiewicz, Paras N. Prasad, Ovidiu
Toader, Sajeev John, Robert W. Boyd, Optics Letters 27, no. 5, 351 (2002). ABSTRACT PDF
- "Semi-classical Theory of Lasing in Photonic Crystals", Lucia Florescu, Kurt Busch, and Sajeev John, J. Optical Society of America B19, 2215 (2002). ABSTRACT PDF
- "Square spiral photonic crystals: Robust architecture for microfabrication of materials with large
three-dimensional photonic band gaps", Ovidiu Toader and Sajeev John, Physical Review E 66, 016610 (2002), ABSTRACT PDF POSTSCRIPT
- "Diffractionless Flow of Light in All-Optical Micro-chips", A. Chutinan, Sajeev John, and O. Toader, Physical Review Letters 90, 123901 (2003) . ABSTRACT PDF POSTSCRIPT
- "Photonic Band Gap Materials based on Tetragonal Lattices of Slanted Pores", O. Toader, M. Berciu, and Sajeev John, Physical Review Letters 90, 233901 (2003). ABSTRACT
- "Photonic Band Gap Synthesis
by Holographic Lithography", Ovidiu Toader, Tim Chan, and Sajeev John, Physical Review Letters 92, 043905 (2004).
ABSTRACT PDF POSTSCRIPT
- "Direct Two-Photon Writing and Characterization of Slanted Pore Photonic
Crystals", Markus Deubel, Martin Wegener, Artan Kaso and Sajeev John, Applied
Physics Letters 85 (11), 1895 (2004).ABSTRACT PDF
- "Photonic band gap enhancement in frequency-dependent dielectrics", Ovidiu Toader and Sajeev John, Physical Review E 70, 046605 (2004). ABSTRACT PDF
- ."Resonance Fluorescence in Photonic Band Gap Waveguide Architectures:
Designing the Vacuum for All-Optical Switching", M. Florescu and Sajeev John, Physical Review A 69, 053810 (2004). ABSTRACT PDF
- "Engineering the Electromanetic Vacuum for Controlling Light with Light in
a Photonic Band Gap Micro-chip", R. Z. Wang and Sajeev John, Physical Review A 70, 043805 (2004). ABSTRACT PDF
- "Sculpting the vacuum in a photonic band gap micro-chip", R.Z. Wang and Sajeev John, Journal of Photonics and Nanostructures 2,
137 (2004). ABSTRACT
- "Diffractionless Flow of Light in 2D-3D Photonic Band Gap
Hetero-structures: Theory, Design Rules, and Simulations", Alongkarn Chutinan and Sajeev John, Physical Review E 71, 026605 (2005). ABSTRACT PDF
- "Pulse re-shaping in photonic crystal waveguides and micro-cavities with
Kerr-nonlinearity: Critical Issues for all-optical switching", Dragan Vujic and Sajeev John, Physical Review A 72, 013807 (2005). ABSTRACT PDF
- "Slanted Pore Photonic Band Gap Materials",
Ovidiu Toader and Sajeev John, Physical Review E 71, 036605 (2005).
- "Photonic Band Gap Synthesis by Optical Interference Lithography", Tim Chan, Ovidiu Toader, and Sajeev John, Physical Review E 71, 046605 (2005). ABSTRACT PDF
- "Sub-nanometer precision tuning of the optical properties of
three-dimensional polymer-based photonic crystals", G. von Freymann, V. Kitaev, T. Chan, Sajeev John, G. Ozin, M. Deubel, M. Wegener, Journal of Photonics and Nanostructures 2, 191-198
(2004). ABSTRACT PDF
- "Measurement of group velocity
dispersion for finite size three-dimensional photonic crystals in the near
infrared spectral region", G. von Freymann, Sajeev John, S. Wong, S. Kitaev, G. Ozin, Applied
Physics Letters 86, 053108 (2005). ABSTRACT PDF
- "Enhanced coupling to slow photon modes of three-dimensional graded colloidal
photonic crystals", Georg von Freymann, Sajeev John, Vladimir Kitaev, Geoffrey A. Ozin,
Advanced Materials, Vol. 17, Issue 10, 1273-1276 (2005). ABSTRACT
- "Light Localization for Broadband Integrated Optics in Three
Dimensions", A. Chutinan and Sajeev John, Physical Review B 72, 16, 161316 (2005).
- "Elastic Photonic Crystals:
From Colour Fingerprinting to Enhancement of Photoluminescence", A. Arsenault, T. J. Clark, G. Von Freymann, E. Vekris, L.
Cademartiri, S. Wong, V. Kitaev, I. Manners, Sajeev John, G. A. Ozin,
Nature Materials 5 (3): 179-184 March (2006). PDF
- "New route towards three-dimensional
photonic band gap materials: Silicon double inversion of Polymeric
Templates", N. Tetreault, G. von Freymann, M. Deubel, M. Hermatschweiler, F. Perez-Willard, Sajeev John, M. Wegener, G.A. Ozin, Advanced Materials 18 (4): 457, Feb 17 (2006). ABSTRACT
- "Direct Laser Writing of Three-Dimensional
Photonic Crystals in High Index of Refraction Chalcogenide Glasses", G. von Freymann, S. Wong, G. A. Ozin, Sajeev John, F. Perez-Willard,
M. Deubel, M. Wegener, Advanced Materials Vol. 18, Issue 3, February,
2006, Pages: 265-269. ABSTRACT
- "3+1 Dimensional Integrated Optics with Localized Light in a
Photonic Band Gap",
A Chutinan and Sajeev John, Optics Express 14 (3): 1266-1279, Feb 6,
- "3D-2D-3D photonic crystal heterostructures by direct laser writing", M. Deubel, M. Wegener, S. Linden, G. Von Freymann, and Sajeev John, Optics Letters 31 (6): 805-807 March 15 ( 2006) ABSTRACT PDF
- "Photonic band-gap formation by optical-phase-mask lithography", Timothy Y. M. Chan, Ovidiu Toader, and Sajeev John, Physical Review E 73, 046610 (2006) ABSTRACT PDF
- ''Nonlinear Bloch waves in resonantly doped photonic crystals'', Artan Kaso and Sajeev John, Physical Review E 74, 046611 (2006) ABSTRACT PDF
- "Localized light orbitals: Basis states for three-dimensional photonic crystal microscale circuits", Hiroyuki Takeda, Alongkarn Chutinan and Sajeev John, Physical Review B 74, 195116 (2006). ABSTRACT PDF POSTSCRIPT
"Diamond photonic band gap synthesis by umbrella holographic lithography",
Ovidiu Toader, Timothy Y. M. Chan, and Sajeev John, Appl. Phys. Lett. 89, 101117 (2006); doi:10.1063/1.2347112 (3 pages) ABSTRACT PDF
- "Electromagnetically Induced Exciton Mobility in a Photonic Band Gap", Sajeev John and Shengjun Yang, Physical Review Lett. 99 , 046801 (2007). ABSTRACT PDF
- "Exciton dressing and capture by a photonic band edge". Shengjun Yang and Sajeev John, Physical Review B 75, 235332 (2007). ABSTRACT PDF
- "Molding light flow from photonic band gap circuits
to microstructured fibers", James Bauer and Sajeev John, Applied Physics Letters 90, 261111(2007). ABSTRACT PDF
- "Nonlinear Bloch waves in metallic photonic band-gap filaments", Artan Kaso and Sajeev John, Physical Review A 76, 053838 (2007). ABSTRACT PDF
- "Coherent all-optical switching by resonant quantum-dot distributions in photonic band-gap
waveguides", Dragan Vujic and Sajeev John, Physical Rreview A 76, 063814 (2007).
- "Enhanced Photoconductivity in Thin-Film Semiconductors
Optically Coupled to Photonic Crystals", Paul G. O'Brien, Nazir P. Kherani, Stefan Zukotynski, Geoffrey A. Ozin, Evangellos Vekris,
Nicolas Tetreault, Alongkarn Chutinan, Sajeev John, Augustin Mihi, and Hernan Miguez, Advanced Materials 19, 4177-4182 (2007)
- "Broadband optical coupling between microstructured fibers and photonic band gap circuits:
Two-dimensional paradigms", James Bauer and Sajeev John, Physical Review A 77, 013819 (2008) ABSTRACT PDF
- "Compact optical one-way waveguide isolators for photonic-band-gap microchips", Hiroyuki Takeda and Sajeev John, Physical Review A 78, 023804 (2008) ABSTRACT PDF
- "Light trapping and absorption optimization in certain thin-film photonic crystal architectures", Alongkarn Chutinan and Sajeev John, Physical Review A 78, 023825 (2008) ABSTRACT PDF
- "Templating and Replication of Spiral Photonic
Crystals for Silicon Photonics", Kock Khuen Seet, Vygantas Mizeikis, Kenta Kannari, Saulius Juodkazis, Hiroaki Misawa,
Nicolas Tetreault, and Sajeev John, IEEE Journal of Selected Topics in Quantum Electronics, Vol. 14, No. 4, July/August (2008). PDF
- "Circuits for light in holographically defined photonic-band-gap materials", Timothy Y. M. Chan and Sajeev John, Physical Review A 78, 033812 (2008) ABSTRACT
- "Exceptional Reduction of the Diffusion Constant in Partially Disordered Photonic Crystals", Costanza Toninelli, Evangellos Vekris, Geoffrey A. Ozin, Sajeev John and Diederik S. Wiersma, Physical Review Letters, 101, 123901 (2008) ABSTRACT
- "Metallic photonic-band-gap filament architectures for optimized incandescent lighting", Sajeev John and Rongzhou Wang, Physical Review A, 78, 043809 (2008) ABSTRACT
- "Optical wavelength converters for photonic band gap microcircuits", Dragan Vujic and Sajeev John, Physical Review A 79, 053836 (2009).
- "Ultrafast Population Switching of Quantum Dots in a Structured Vacuum", Xun Ma and Sajeev John, Physical Review Lett. 103, 233601 (2009). ABSTRACT PDF
- "Switching dynamics and ultrafast inversion control of quantum dots
for on-chip optical information processing". Xun Ma and Sajeev John, Physical Review A 80, 063810 (2009). ABSTRACT PDF
- "Microscopic theory of multiple-phonon-mediated dephasing and relaxation of quantum dots near a photonic band gap", Chiranjeeb Roy and Sajeev John, Physical Review A
81, 023817 (2010). ABSTRACT PDF
- "Self-consistent Maxwell-Bloch theory of quantum-dot-population switching in photonic
crystals" Hiroyuki Takeda and Sajeev John,
Physical Review A 83, 053811 (2011).
- "Coherence and antibunching in a trapped interacting Bose-Einstein condensate" Shengjun Yang and Sajeev John, Physical Review B 84, 024515 (2011). ABSTRACT PDF
- "Quantum-dot all-optical logic in a structured vacuum", Xun Ma and Sajeev John, Physical Review A 84, 013830 (2011). ABSTRACT PDF
- "Optical pulse dynamics for quantum-dot logic operations in a photonic-crystal waveguide", Xun Ma and Sajeev John, Physical Review A 84, 053848 (2011). ABSTRACT PDF
- "Anomalous flow of light near a photonic crystal
pseudo-gap", Kyle M. Douglass, Sajeev John, Takashi Suezaki, Geoffrey A. Ozin, and Aristide
Dogariu1, Optics Express, 19, No. 25 , 25321 (2011). ABSTRACT PDF
- "Sculpturing of photonic crystals by ion beam lithography: towards complete
photonic bandgap at visible wavelengths", Saulius Juodkazis, Lorenzo Rosa, Sven Bauerdick, Lloyd Peto,
Ramy El-Ganainy and Sajeev John, Optics Express, 19, No. 7 , 5803 (2011).
- "Effective optical response of silicon to sunlight
in the finite-difference time-domain method", Alexei Deinega and Sajeev John,
Optics Letters, 37, No. 1 112 (2012).
- "Solar energy trapping with modulated silicon nanowire photonic crystals", Guillaume Demesy and Sajeev John, J. Appl. Phys., 112, 074326 (2012).
- "Solar power conversion efficiency in modulated silicon nanowire photonic
crystals", Alexei Deinega and Sajeev John, J. Appl. Phys. 112, 074327 (2012).
- "Light-trapping in dye-sensitized solar cells", Stephen Foster and Sajeev John,
Energy Environ. Sci., DOI: 10.1039/C3EE40185E (2013).
- "Solar light trapping in slanted conical-pore photonic crystals: Beyond
statistical ray trapping", Sergey Eyderman, Sajeev John, and Alexei Deinega, J. Appl. Phys. 113, 154315 (2013); doi: 10.1063/1.4802442.
- "Finite difference discretization of semiconductor drift-diffusion equations for
nanowire solar cells", Alexei Deinega and Sajeev John, Computer Physics Communications 183, 2128 (2012).
- "Coupled optical and electrical modeling of solar cell based on
conical pore silicon photonic crystals", Alexei Deinega, Sergey Eyderman, and Sajeev John, Journal of Applied Phys. 113, 224501 (2013); doi: 10.1063/1.4809982. ABSTRACT
- "Resonant dipole-dipole interaction in confined and
strong-coupling dielectric geometries", Ramy El-Ganainy and Sajeev John, New Journal of Physics, 15, 083033 (2013).
- "Macroscopic response in active nonlinear
photonic crystals", Gandhi Alagappan,Sajeev John, and Er Ping Li, Optics Letters 38, No. 18, 3514 (2013).
- "Light trapping and near-unity solar absorption in
a three-dimensional photonic-crystal", Ping Kuang, Alexei Deinega, Mei-Li Hsieh, Sajeev John and Shawn-Yu Lin, Optics Letters 38, No. 20, 4200 (2013).
- "Synergistic plasmonic and photonic crystal lighttrapping:
Architectures for optical upconversion
in thin-film solar cells", Khai Q. Le and Sajeev John, Optics Express, 22, Issue S1, pp. A1-A12, DOI:10.1364/OE.22.0000A1 (2014).
- "Near perfect solar absorption in ultra-thin-film
GaAs photonic crystals", Sergey Eyderman, Alexei Deinega and Sajeev John, Journal of
Materials Chemistry A, DOI: 10.1039/c3ta13655h (2014).
- "Light trapping design for low band-gap polymer solar cells," Stephen Foster and Sajeev John, Optics Express, Vol. 22, Issue S2, pp. A465-A480 (2014).
- "Photonic Crystal Architecture for Room-Temperature Equilibrium Bose-Einstein
Condensation of Exciton Polaritons," Jian-Hua Jiang and Sajeev John, Physical Review X 4, 031025 (2014).
- "Photonic Architectures for Equilibrium High-Temperature Bose-Einstein Condensation in Dichalcogenide Monolayers," Jian-Hua Jiang & Sajeev John,
Nature Magazine Scientific Reports 4, 7432 (2014).
- "Optical Biosensing of Multiple Disease Markers in a Photonic-Band-Gap Lab-on-a-Chip: A Conceptual Paradigm," Abdullah Al-Rashid and Sajeev John,
Phys. Rev. Applied 3, 034001 (2015).
- "Light-trapping optimization in wet-etched silicon photonic crystal solar cells,"
Sergey Eyderman, Sajeev John, M. Hafez, S. S. Al-Ameer, T. S. Al-Harby, Y. Al-Hadeethi, and D. M. Bouwes, Journal of Applied Physics 118, 023103 (2015).
- "Waveguide-mode polarization gaps in square spiral photonic crystals,"
Rong-Juan Liu, Sajeev John and Zhi-Yuan Li, EPL, 111 54001 (2015).
"Biosensor architecture for enhanced disease diagnostics: lab-in-a-photonic-crystal," Shuai Feng, Jian-Hua Jiang, Abdullah Al Rashid and Sajeev
John, Optics Express, 24 No. 11, 12166 (2016).
- "Light-trapping in perovskite solar cells," Qing Guo Du, Guansheng Shen and Sajeev John, AIP Advances 6, 065002 (2016).
- "Light-trapping for room temperature Bose-Einstein condensation in InGaAs quantum wells," Pranai Vasudev, Jian-Hua Jiang and Sajeev John, Optics Express 24 No.13, 14010 (2016). ABSTRACT
- "Light-trapping and recycling for extraordinary power conversion in ultra-thin gallium-arsenide solar cells," Sergey Eyderman and Sajeev John, Nature Scientific Reports 6 28303 (2016). ABSTRACT
- "Achieving an Accurate Surface Profile of a Photonic Crystal for Near-Unity Solar Absorption in a Super Thin-Film Architecture," Ping Kuang, Sergey Eyderman, Mei-Li Hsieh, Anthony Post, Sajeev John and Shawn-Yu Lin, ACS, Nano 10 (6) 6116-6124 (2016). ABSTRACT
- "Probing the intrinsic optical Bloch-mode emission from a 3D photonic crystal," Mei-Li Hsieh1, James A Bur, Qingguo Du, Sajeev John and Shawn-Yu Lin, Nanotechnology
27 415204 (2016). ABSTRACT
- "Light-trapping design for thin-film silicon-perovskite tandem solar cells," Stephen Foster and Sajeev John, Journal of Applied Physics 120, 103103 (2016).
- "Effectively infinite optical pathlength created using a simple cubic photonic crystal for extreme light trapping," Brian J. Frey, Ping Kuang, Mei-Li Hsieh, Jian-Hua Jiang,
Sajeev John and Shawn-Yu Lin, Scientific Reports 7, Article number: 4171 (2017).
MULTIPLE LIGHT SCATTERING, MEDICAL IMAGING, AND RANDOM LASERS
Multiple scattering of light in biological tissue provides a safe, inexpensive,
and noninvasive probe of brain, breast, and skin tumors. Unlike, magnetic
resonance imaging (MRI) which relies on very long wavelength radiation,
or X-ray based tomography which relies on very short wavelength radiation,
the optical method utilizes an intermediate wavelength window. This
window is sensitive to the concentration of oxygenated haemoglobin in tissue,
and thereby provides an early diagnostic image of metabolic processes
leading to cancer, prior to structural damage caused by the tumor.
We are developing a microscopic
theory of the propagation of the Wigner coherence function (two-point
electric field correlation function) of near infra-red light propagating
and scattering in biological tissue which contains a statistical inhomogeneity
(tumor). The inhomogeneity exhibits preferential absorption of light and
may have different scattering characteristics than healthy tissue. The
optical Wigner function is sensitive to these different absorption and
scattering characteristics. The difficulty of the optical method is that,
unlike X-ray and MRI techniques in which radiation propagates in a straight
line, light undergoes a complicated
multiple scattering path in the medium. Our work is aimed at unscrambling
the information about tissue characteristics contained in the optical wave-field
after it has been scattered many times. Most other researchers in this
field have adopted the simplistic assumption that photons (particles of
light) can be regarded as classical particles undergoing diffusion in the
tissue. Using this assumption, tissue properties can only be resolved on
the scale of a millimeter. Our approach, which for the first time solves
the wave equation and relates the Wigner coherence function to the tissue
dielectric constant, will improve the resolution of the optical method
by several orders of magnitude. Our microscopic theory will facilitate
the reconstruction of tissue images with a resolution on the scale of the
optical wavelength. Imaging devices based on our theory will be safe,
inexpensive, and suitable for use in the office of the general practitioner.
Other applications include the ability to diagnose skin tumors without
recourse to a biopsy and the ability to perform a blood test without
having to draw blood.
Biological tissue is a weakly absorbing, multiple light scattering medium.
A closely related problem is that of stimulated emission, optical amplification
and lasing in a random medium with gain. Recent experiments have revealed
that a multiple scattering medium doped with dye molecules can exhibit
isotropic laser action when suitably pumped. We have developed a comprehensive microscopic theory of these "Random Lasers".
S. John and M. Stephen, Phys. Rev. B28, 6358 (1983) "Wave Propagation
and Localization in a Long Range Correlated Random Potential". ABSTRACT PDF
Sajeev John, Phys. Rev. B 31, 304 (1985) "Localization and Absorption
of Waves in a Weakly Dissipative Disordered Medium". ABSTRACT
S. Etemad, R. Thompson, M.J. Andrejco, Sajeev John and F. MacKintosh, Phys.
Rev. Lett. 59, 1420, (1987) "Weak Localization of Photons: Termination
of Coherent Random Walks by Absorption and Confined Geometry". ABSTRACT
Fred MacKintosh and Sajeev John, Phys. Rev. B 37, 1884 (1988) "Coherent
Backscattering of Light in the Presence of Time Reversal Non-invariant
and Parity Violating Media". ABSTRACT
F. MacKintosh and S. John, Phys. Rev. B40, 2383 (1989) "Diffusing-Wave
Spectroscopy and Multiple Scattering of Light in Correlated Random Media".
S. John, G. Pang and Y. Yang, Journal of Biomedical Optics, Volume 1, No.
2, page 180 (1996) "Optical Coherence Propagation and Imaging in a Multiple
Scattering Medium". ABSTRACT
Sajeev John and Gendi Pang, Physical Review A 54, 3642 (1996) ''Theory
of Lasing in a Multiple Scattering Medium''. ABSTRACT
Sajeev John, Nature, 390 661 (1997) "Frozen Light". ABSTRACT
- ''Theory of Photon Statistics and Optical Coherence in a Multiple-Scattering Random Laser Medium'', Lucia Florescu and Sajeev John, Physical Review E 69, 046603 (2004). ABSTRACT
- ''Lasing in a random amplifying medium: Spatiotemporal characteristics and
nonadiabatic atomic dynamics'', Lucia Florescu and Sajeev John Physical Review E 70, 036607 (2004) . ABSTRACT
- ''Photon Statistics and Optical Coherence Properties of Light
Emission from a Random Laser'', Lucia Florescu and Sajeev John, Physical Review Letters 93, 013602
MAGNETISM AND SUPERCONDUCTIVITY
The microscopic mechanism for high temperature superconductivity is one
of foremost unsolved problems in solid state physics. A clear understanding
of this mechanism may lead to the design of new materials which exhibit
superconductivity at room temperature. This would lead to a technological
revolution rivaling the semiconductor and the laser.
The central question in this field is the nature of the, parent,
non-Fermi-liquid metallic state of a strongly interacting electron gas
from which superconductivity emerges. This parent state differs from
that of ordinary superconductors in a highly fundamental way. One aspect
of the unconventional nature of the parent metal is the appearance of antiferromagnetism
at very low charge carrier concentration and the disappearance of this
magnetic state with increasing carrier concentration. Recently, our work
has revealed the existence of topological
magnetic solitons in such an electron gas as well as a novel
magnetic phase of these systems, which we refer to as a spin-flux
phase. When electrons are added to this system, this background magnetic
state causes the spin and the charge of the electrons to separate and
become bound to magnetic vortex solitons. These vortex solitons are
the 2-d analogues of domain wall solitons in 1-d polyacetylene. They
induce mid-gap electronic levels in the Mott-Hubbard charge transfer gap
In this state the electron gas no longer acts as a Fermi liquid, in agreement
with experiments. The appearance of these solitons also leads to the observed
disappearance of long range antiferromagnetic order in the spin background.
We are developing a microscopic theory of the anomalous metallic
phase and superconducting phase of the high temperature cuprate superconductors
based on these concepts. Our current work involves the calculation of the
Hartree-Fock energies of various magnetic solitons, the determination of
the spin, charge, and statistics of
these solitons, and the nature of the thermodynamic phases formed by
a finite density of these solitons. We are studying the linear and nonlinear
response of charged and uncharged to solitons to external electromagnetic
fields. A detailed comparison of our model with experimentally observed
magnetic, optical, and electronic properties of high temperature superconducting
materials is being performed.
Sajeev John and T.C. Lubensky, Phys. Rev. B 34, 4815 (1986) "Phase
Transitions in a Disordered Superconductor near Percolation". ABSTRACT
S. John, P. Voruganti and W. Goff, Phys. Rev. B43, 13, 365 (1991)
"Electronic and Magnetic Features of Twisted Spin-Density-Wave States in
the Two-dimensional Hubbard Model". ABSTRACT
P. Voruganti, A. Golubentsev and Sajeev John, Phys. Rev. B45 13945
(1992) "Conductivity and Hall Effect in the Two Dimensional Hubbard Model".
S. John and A. Golubentsev, Phys. Rev. Lett. 71, 3343 (1993) "Topological
Magnetic Solitons in the Two-dimensional Mott-Hubbard Gap". ABSTRACT
S. John and A. Golubentsev, Phys. Rev. B51, 381 (1995) "Spin-flux
and Magnetic Solitons in an Interacting Two-dimensional Electron Gas: Topology
of Two-Valued Wavefunctions". ABSTRACT
S. John and A. Muller-Groeling, Phys. Rev. B51, 12989 (1995) "Mean-field
Energies of Spin-flux Phases". ABSTRACT
Sajeev John, Mona Berciu and A. Golubentsev, Europhysics Letters
(1), 31 (1998) "Midgap States of a Two-Dimensional Antiferromagnetic Mott
Insulator: Electronic Structure of Meron-Vortices". ABSTRACT
Mona Berciu and Sajeev John, Physical Review B57, 9521 (1998) "Charged
Bosons in a Doped Mott Insulator: Electronic Properties of Domain Wall
Solitons and Meron-Vortices". ABSTRACT
Mona Berciu and Sajeev John, Physical Review B 59, 15143 (1999)
"Numerical study of multisoliton configurations in a doped antiferromagnetic
Mott insulator". ABSTRACT PDF
Mona Berciu and Sajeev John, Physical Review B 61 (15), 10015-10028 (2000) "Quantum dynamics of charged and neutral magnetic
solitons: Spin-charge separation in the one-dimensional Hubbard model".
ABSTRACT PDF POSTSCRIPT
Mona Berciu and Sajeev John, Physical Review B 61 (24), 16454-16469 (2000) "A microscopic model for d-wave charge carrier
pairing and non-Fermi-liquid behavior in a purely repulsive 2D electron
system". ABSTRACT PDF POSTSCRIPT
- "Magnetic structure factor in cuprate superconductors: Evidence for charged meron vortices", Mona Berciu and Sajeev John, Physical Review B 69, 224515 (2004). ABSTRACT PDF
Photon Localization and Photonic Bandgap Materials
| Multiple Light Scattering, Medical Imaging and Random Lasers
| Magnetism and Superconductivity
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