YuShibaRusinov states in phasebiased superconductorquantum dotsuperconductor junctions
(2015) In Physical Review B (Condensed Matter and Materials Physics) 92(23). Abstract
 We study the effects of a phase difference on YuShibaRusinov (YSR) states in a spinful Coulombblockaded quantum dot contacted by a superconducting loop. In the limit where charging energy is larger than the superconducting gap, we determine the subgap excitation spectrum, the corresponding supercurrent, and the differential conductance as measured by a normalmetal tunnel probe. In absence of a phase difference only one linear combination of the superconductor lead electrons couples to the spin, which gives a single YSR state. With finite phase difference, however, it is effectively a twochannel scattering problem and therefore an additional state emerges from the gap edge. The energy of the phasedependent YSR states depend on the... (More)
 We study the effects of a phase difference on YuShibaRusinov (YSR) states in a spinful Coulombblockaded quantum dot contacted by a superconducting loop. In the limit where charging energy is larger than the superconducting gap, we determine the subgap excitation spectrum, the corresponding supercurrent, and the differential conductance as measured by a normalmetal tunnel probe. In absence of a phase difference only one linear combination of the superconductor lead electrons couples to the spin, which gives a single YSR state. With finite phase difference, however, it is effectively a twochannel scattering problem and therefore an additional state emerges from the gap edge. The energy of the phasedependent YSR states depend on the gate voltage and one state can cross zero energy twice inside the valley with odd occupancy. These crossings are shifted by the phase difference towards the charge degeneracy points, corresponding to larger exchange couplings. Moreover, the zeroenergy crossings give rise to resonant peaks in the differential conductance with magnitude 4e(2)/h. Finally, we demonstrate that the quantum fluctuations of the dot spin do not alter qualitatively any of the results. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/record/8556937
 author
 Kirsanskas, Gediminas ^{LU} ; Goldstein, Moshe; Flensberg, Karsten; Glazman, Leonid I. and Paaske, Jens
 organization
 publishing date
 2015
 type
 Contribution to journal
 publication status
 published
 subject
 in
 Physical Review B (Condensed Matter and Materials Physics)
 volume
 92
 issue
 23
 publisher
 American Physical Society
 external identifiers

 wos:000366493300006
 scopus:84950335624
 ISSN
 10980121
 DOI
 10.1103/PhysRevB.92.235422
 language
 English
 LU publication?
 yes
 id
 63050f1600f04299a419c2be6963a2d2 (old id 8556937)
 date added to LUP
 20160126 13:54:18
 date last changed
 20180128 03:48:53
@article{63050f1600f04299a419c2be6963a2d2, abstract = {We study the effects of a phase difference on YuShibaRusinov (YSR) states in a spinful Coulombblockaded quantum dot contacted by a superconducting loop. In the limit where charging energy is larger than the superconducting gap, we determine the subgap excitation spectrum, the corresponding supercurrent, and the differential conductance as measured by a normalmetal tunnel probe. In absence of a phase difference only one linear combination of the superconductor lead electrons couples to the spin, which gives a single YSR state. With finite phase difference, however, it is effectively a twochannel scattering problem and therefore an additional state emerges from the gap edge. The energy of the phasedependent YSR states depend on the gate voltage and one state can cross zero energy twice inside the valley with odd occupancy. These crossings are shifted by the phase difference towards the charge degeneracy points, corresponding to larger exchange couplings. Moreover, the zeroenergy crossings give rise to resonant peaks in the differential conductance with magnitude 4e(2)/h. Finally, we demonstrate that the quantum fluctuations of the dot spin do not alter qualitatively any of the results.}, articleno = {235422}, author = {Kirsanskas, Gediminas and Goldstein, Moshe and Flensberg, Karsten and Glazman, Leonid I. and Paaske, Jens}, issn = {10980121}, language = {eng}, number = {23}, publisher = {American Physical Society}, series = {Physical Review B (Condensed Matter and Materials Physics)}, title = {YuShibaRusinov states in phasebiased superconductorquantum dotsuperconductor junctions}, url = {http://dx.doi.org/10.1103/PhysRevB.92.235422}, volume = {92}, year = {2015}, }