John
Y.T. Wei
Associate
Professor
Condensed Matter Physics |
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Background
Scholar, Canadian Institute for Advanced Research (since 1999) Member, Centre for Quantum Information and Quantum Control (since 2004) Member, Brockhouse Institute for Materials Research (since 2003) Postdoctoral Scholar & Research Fellow, California Institute of Technology (1996-99) Joint Research Student, IBM T. J. Watson Research Center (1992-95) M.S. & Ph.D., Columbia University (1991 & 1996) B.A.,
University
of
California
Berkeley
(1987)
Interests:
Nanoscale studies of exotic superconductivity,
extreme magnetism & topological phenomena in
oxides & intermetallics.
Materials: Transition-metal oxides/chalcogenides, Fe-chalcogenides/pnictides, CeCoIn5, Skutterudites, heavy-metal chalcogenides. Techniques: Cryomagnetic scanning tunneling microscopy (STM) & point-contact spectroscopy (PCS), pulsed laser deposition (PLD). My
research is devoted to nanoscale study of
unconventional superconducting and magnetic materials,
as well as the emerging new class of topological
materials. It is intended to examine the
electronic properties of these materials at very short
length scales, where the quantum ordering effects
occur coherently without being averaged out over
macroscopic distances, and manifest themselves as
novel phenomena. It involves an unique
combination of cryomagnetic, nanoprobe and
nanofabrication techniques, with the application of
both “top-down” and “bottom-up” approaches.
Detailed understanding of these exotic electronic
materials is of fundamental importance to condensed
matter physics, and could also lend them to novel
technological applications, ranging from
superconducting to spintronic devices, as well as
elements for quantum computation.
Courses
Taught Physics 294H:
Thermal Physics for Engineering Sciences
Physics 335H: Quantum Mechanics for Electrical & Computer Engineering Physics 1850F: Foundations of Condensed Matter Physics Physics 326/327: 3rd/4th-Year Undergraduate Laboratory Physics 225H: 2nd-Year Undergraduate Laboratory Physics 281S: Introduction to Quantum Physics
Select
Publications 1. Lateral Imaging of the
Superconducting Vortex Lattice using Doppler
Modulated Scanning Tunneling Microscopy Nuclear Spin Relaxation
of 8Li
in a Thin
Film of La_0.67Ca_0.33MnO_3 Evidence for
Current-Driven Phase Slips in YBa_2Cu_3O_7-d Microstrips Point Contact
Spectroscopy Study of the Ferromagnetic
Superconductor ZrZn_2 Selective
epitaxial growth of sub-micron complex oxide
structures by amorphous SrTiO_3 Scanning tunneling
spectroscopy under pulsed spin injection Nanoscale
high-temperature superconductivity Tunneling
spectroscopy study of spin-polarized quasiparticle
injection effects in
Directional
tunneling and Andreev reflection on
YBa_2Cu_3O_{7-delta} single crystals:
Predominance of d-wave pairing symmetry verified with the generalized BTK theory, J. Y. T. Wei et al., Physical Review Letters 81, 2542 (1998). Quasiparticle tunneling spectra of the high-Tc mercury cuprates: implication of the d-wave two-dimensional van Hove scenario, J. Y. T. Wei et al., Physical Review B 57, 3650 (1998). |
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University
of Toronto |
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