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Publications

Theory of the nodal nematic quantum phase transition in superconductors

Cornell Affiliated Author(s)
Author
Eun-Ah Kim
M.J. Lawler
P. Oreto
S. Sachdev
E. Fradkin
S.A. Kivelson
Abstract

We study the character of an Ising nematic quantum phase transition deep inside a d -wave superconducting state with nodal quasiparticles in a two-dimensional tetragonal crystal. We find that, within a 1/N expansion, the transition is continuous. To leading order in 1/N, quantum fluctuations enhance the dispersion anisotropy of the nodal excitations and cause strong scattering, which critically broadens the quasiparticle (qp) peaks in the spectral function, except in a narrow wedge in momentum space near the Fermi surface where the qps remain sharp.

Journal
Physical Review B - Condensed Matter and Materials Physics
Date Published
Group (Lab)
Michael Lawler Group

Non-abelian statistics in the interference noise of the Moore-Read quantum Hall state

Cornell Affiliated Author(s)
Author
E. Ardonne
Eun-Ah Kim
Abstract

We propose noise oscillation measurements in a double point contact, accessible with current technology, to seek for a signature of the non-abelian nature of the ν = 5/2 quantum Hall state. Calculating the voltage and temperature dependence of the current and noise oscillations, we predict the non-abelian nature to materialize through a multiplicity of the possible outcomes: two qualitatively different frequency dependences of the nonzero interference noise.

Journal
Journal of Statistical Mechanics: Theory and Experiment
Date Published
Group (Lab)