Influence of Charge and Energy Imbalances on the Tunneling Current through a Superconductor-Normal Metal Junction

Abstract

We consider quasiparticle charge and energy imbalances in a thin superconductor weakly coupled with two normal-metal electrodes via tunnel junctions at low temperatures. Charge and energy imbalances, which can be created by injecting quasiparticles at one junction, induce excess tunneling current $I_{\mathrm{ex}}$ at the other junction. We numerically obtain $I_{\mathrm{ex}}$ as a function of the bias voltage $V_{\det }$ across the detection junction. We show that $I_{\mathrm{ex}}$ at the zero bias voltage is purely determined by the charge imbalance, while the energy imbalance causes a nontrivial $V_{\det }$-dependence of $I_{\mathrm{ex}}$. The obtained voltage-current characteristics qualitatively agree with the experimental result by R. Yagi [Phys. Rev. B {\bf 73} (2006) 134507].

10 pages, 5 figures

References in corpus (1)

• Boltzmann Equations for Spin and Charge Relaxations in Superconductors

Cited by in corpus (3)

• Charge imbalance in superconductors in the low-temperature limit
• Spin Injection and Detection in a Mesoscopic Superconductor at Low Temperatures
• Nonequilibrium electron distribution function in a voltage-biased nanowire: A nonequilibrium Green's function approach