Steve Simon

Abstract:

Directly observing a zero energy Majorana state in the vortex core of a chiral superconductor by tunneling spectroscopy requires energy resolution better than the spacing between core states Δ02/ F. We show that, nevertheless, its existence can be decisively tested by comparing the temperature-broadened tunneling conductance of a vortex with that of an antivortex even at temperatures T≫Δ02/ F. © 2008 The American Physical Society.

Abstract:

We provide numerical evidence for composite fermion pairing in quantum Hall bilayer systems at filling ν=12+12 for intermediate spacing between the layers. We identify the phase as px+ipy pairing, and construct high accuracy trial wave functions to describe the ground state on the sphere. For large distances between the layers, and for finite systems, a competing "Hund's rule" state, or composite fermion liquid, prevails for certain system sizes. © 2008 The American Physical Society.