Smitha Vishveshwara
Assistant Professor of Physics
Professor Smitha Vishveshwara received her bachelor's degree in physics magna cum laude from Cornell University in 1996, and her Ph.D in
theoretical physics from the University of California, Santa Barbara, in 2002. She served as a postdoctoral research associate with
Paul Goldbart and
Tony Leggett from 2002 to 2005, working on tunneling and
fractional statistics in quantum Hall systems, Aharonov-Bohm effects in carbon nanotubes
(as reported in
Science),
and critical dynamics in charged superconductors. She joined the department as an assistant professor in August 2005.
Professor Vishveshwara's research interests span a broad range of topics in theoretical condensed matter physics, and she maintains strong collaborative ties with experimentalists. Over the next few years, she plans to extend ongoing projects, to expand her research into problems involving ultracold atoms trapped in optical lattices, electronic properties of single-walled nanotubes, and exotic features of quantum Hall states.
Research areas: theoretical condensed matter physics, particularly strongly correlated systems-disordered systems, localization physics, phase transitions, critical dynamics, superconductivity, Luttinger liquids, quantum Hall systems, carbon nanotubes, optical lattices
Description of Current Research
Co-existence of quantum phases in optical lattices
Interacting bosons confined to a pure lattice can exhibit either Mott insulating behavior, where constituent particles
are pinned to lattice sites, or superfluid order, where particles are delocalized over sites. Under certain conditions, trapped bosons in
optical lattices can display co-existence of the two phases. Professor Vishveshwara's current research involves various aspects of these
co-existent phases, such as collective behavior, dynamics, and critical properties. Her collaborative efforts have explored the conditions for realizing
multiple Mott insulating phases in optical lattices and their signatures
in spectroscopic measurements.
Probing hallmarks of fractional quantum Hall systems via tunneling
The natural quasiparticle excitations of the fractional quantum Hall (FQH) system
are bizarre objects whose identity is "orthogonal" to the constituent electrons. In particular, these particles are predicted to have
fractional charge and fractional statistics. Professor Vishveshwara has proposed a Hall bar setup
for making measurements analogous to those of the Hanbury Brown-Twiss experiment,
which revealed the bosonic statistics of photons some decades ago. With her collaborators, she has shown that appropriate correlations of quasiparicle
tunneling current exhibit signatures of both fractional statistics and fractional charge.
Professor Vishveshwara has also explored the possibility of Cooper-pair tunneling from a superconducting lead into singlet FQH states. Such a setup could
enable filtering and locking into specific FQH states. Furthermore, under certain conditions, it could enable Cooper pairs
to split into constituent electrons that tunnel into two edge states.
View Professor Vishveshwara's lecture, " Uncovering Fractional Statistics Via a Hanbury Brown Twiss Setup," presented at the Kavli Institute of Theoretical Physics, June 10, 2003.
Selected Publications
E.-A. Kim, M. Lawler, S. Vishveshwara, and E. Fradkin, " Signatures of fractional statistics in noise experiments in quantum Hall fluids," Phys. Rev. Lett. 95, 176402-1-4 (2005).
T.-C. Wei, D. Das, S. Mukhopadyay, S. Vishveshwara, and P.M. Goldbart, "Global entanglement and quantum criticality in spin chains," Phys. Rev. A 71, 060305-1-4 (2005).
B. DeMarco, C. Lannert, S. Vishveshwara, and T.-C. Wei, "Structure and stability of Mott-insulator shells of bosons trapped in an optical lattice," Phys. Rev. A 71, 063601 (2005).
U.C. Coskun, T.-C. Wei. S. Vishveshwara, P.M. Goldbart, and A. Bezryadin, "h/e magnetic flux modulation of the energy gap in nanotube quantum dots," Science 304, 1132-1134 (2004).
C. Lannert, S. Vishveshwara, and M.P.A. Fisher, "Critical dynamics of superconductors in the charged regime," Phys. Rev. Lett. 92, 097004/1-4 (2004).
E.-A. Kim, S. Vishveshwara, and E. Fradkin, "Cooper-pair tunneling in junctions of singlet quantum Hall states and superconductors," Phys. Rev. Lett. 93, 266803 (2004).
S. Vishveshwara, "Revisiting the Hanbury Brown-Twiss setup for fractional statistics," Phys. Rev. Lett. 91, 196803/1-4 (2003).
honors and awards
National Science Foundation CAREER Award, 2007
