Coulomb-blockade-induced bound quasiparticle states in a double-island qubit

Details Coulomb-blockade-induced bound quasiparticle states in a double-island qubit Coulomb-blockade-induced bound quasiparticle states in a double-island qubit

2004-04-20

arxiv.org/abs/cond-mat/0404450v1

Phys. Rev. Lett. 93, 196808 (2004)

Physics

Condensed Matter

Mesoscale and Nanoscale Physics

4 pages, 3 Postscript figures

Scientific paper

10.1103/PhysRevLett.93.196808

We study the low temperature thermodynamic properties of a superconducting double-island qubit. For an odd number of electrons in the device, the ground state corresponds to the intrinsic quasiparticle bound to the tunneling contact. The ground state is separated from the continuum of excited states by a finite gap of order of the Josephson energy E_J. The presence of the bound quasiparticle state results in a nonmonotonic temperature dependence of the width of the transition region between Coulomb blockade plateaus. The minimum width occurs at the ionization temperature of the bound state, T_i\sim E_J/\ln(\sqrt{\Delta E_J}/\delta), with \Delta and \delta being respectively the superconducting gap and single particle mean level spacing in the island. For an even number of electrons in the system, we show that the Coulomb enhancement of the Josephson energy can be significantly stronger than that in the case of a single grain coupled to a superconducting lead. If the electrostatic energy favors a single broken Cooper pair, the resulting quasiparticles are bound to the contact with an energy that is exponentially small in the inverse dimensionless conductance.

Affiliated with

Also associated with

No associations

Rating

Coulomb-blockade-induced bound quasiparticle states in a double-island qubit does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Coulomb-blockade-induced bound quasiparticle states in a double-island qubit, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Coulomb-blockade-induced bound quasiparticle states in a double-island qubit will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-55325