Paul Oreto | Searcharxiv

arXiv2011

Local Interlayer Tunneling Between Two-Dimensional Electron Systems in the Ballistic Regime

We study a theoretical model of virtual scanning tunneling microscopy (VSTM), a proposed application of interlayer tunneling in a bilayer system to locally probe a two-dimensional electron system (2DES) in a semiconductor heterostructure. We consider tunneling for the case where transport in the 2DESs is ballistic, and show that the zero-bias anomaly is suppressed by extremely efficient screening. Since such an anomaly would complicate the interpretation of data from a VSTM, this result is encouraging for efforts to implement such a microscopy technique.

cond-mat.mes-hall↗

arXiv2008

Theory of the nodal nematic quantum phase transition in superconductors

We study the character of an Ising nematic quantum phase transition (QPT) 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 qp's remain sharp. We also consider the possible existence of a nematic glass phase in the presence of weak disorder. Some possible implications for cuprate physics are also discussed.

cond-mat.supr-con↗