Tuesday, March 12, 2013

1303.2407 (H. O. H. Churchill et al.)

Superconductor-Nanowire Devices from Tunneling to the Multichannel
Regime: Zero-Bias Oscillations and Magnetoconductance Crossover
   [PDF]

H. O. H. Churchill, V. Fatemi, K. Grove-Rasmussen, M. T. Deng, P. Caroff, H. Q. Xu, C. M. Marcus
We present transport measurements in superconductor-nanowire devices with a gated constriction forming a quantum point contact. Zero-bias features in tunneling spectroscopy appear at finite magnetic fields, and oscillate in amplitude and split away from zero bias as a function of magnetic field and gate voltage. A crossover in magnetoconductance is observed: Magnetic fields above ~ 0.5 T enhance conductance in the low-conductance (tunneling) regime but suppress conductance in the high-conductance (multichannel) regime. We consider these results in the context of Majorana zero modes as well as alternatives, including Kondo effect and analogs of 0.7 structure in a disordered nanowire.
View original: http://arxiv.org/abs/1303.2407

No comments:

Post a Comment