The interplay between superconductivity and the Kondo effect has stimulated significant interest in condensed matter physics.They compete when their critical temperatures are close and can give rise to a quantum phase...The interplay between superconductivity and the Kondo effect has stimulated significant interest in condensed matter physics.They compete when their critical temperatures are close and can give rise to a quantum phase transition that can mimic Majorana zero modes.Here,we have fabricated and measured Al-InSb nanowire quantum dot-Al devices.In the Kondo regime,a supercurrent-induced zero-bias conductance peak emerges.This zero-bias peak shows an anomalous negative magnetoresistance(NMR)at weak magnetic fields.We attribute this anomalous NMR to quasiparticle trapping at vortices in the superconductor leads as a weak magnetic field is applied.The trapping effect lowers the quasiparticle-caused dissipation and thus enhances the Josephson current.This work connects the vortex physics and the supercurrent tunneling in Kondo regimes and can help further understand the physics of Josephson quantum dot system.展开更多
基金supported by the Swedish Research Council(VR)the National Natural Science Foundation of China(Grant Nos.92165208,11874071,91221202,91421303,and 11904399)+7 种基金the National Key Research and Development Program of China(Grant Nos.2016YFA0300601,and 2017YFA0303304)Beijing Academy of Quantum Information Sciences(Grant No.Y18G22)the financial supports by Hunan Provincial Science Foundation for Distinguished Young Scholars(Grant No.2021JJ10043)the Innovation Program for Quantum Science and Technology(Grant No.2021ZD0302401)the financial support by the Spanish Ministry of Economy and Competitiveness(Grant No.PID2020-117347GBI00)the financial supports by the Spanish Ministry of Economy and Competitiveness(Grant No.PID2020-11778GB-I00)the Mara de Maeztu project CEX2021-001164-M funded by the MCIN/AEI/10.13039/501100011033the supports from CSIC Research Platform PTI-001 and through the grant LINKB20072(CSIC)。
文摘The interplay between superconductivity and the Kondo effect has stimulated significant interest in condensed matter physics.They compete when their critical temperatures are close and can give rise to a quantum phase transition that can mimic Majorana zero modes.Here,we have fabricated and measured Al-InSb nanowire quantum dot-Al devices.In the Kondo regime,a supercurrent-induced zero-bias conductance peak emerges.This zero-bias peak shows an anomalous negative magnetoresistance(NMR)at weak magnetic fields.We attribute this anomalous NMR to quasiparticle trapping at vortices in the superconductor leads as a weak magnetic field is applied.The trapping effect lowers the quasiparticle-caused dissipation and thus enhances the Josephson current.This work connects the vortex physics and the supercurrent tunneling in Kondo regimes and can help further understand the physics of Josephson quantum dot system.
