TY - JOUR
T1 - Mixed-valence transition in a quantum dot coupled to superconducting and spin-polarized leads
AU - Lee, Minchul
AU - Choi, Mahn Soo
N1 - Funding Information:
This work was supported by the National Research Foundation of Korea (Grants No. 2018R1A5A6075964, No. NRF-2017R1E1A1A03070681, and No. 2018R1A4A1024157), the Ministry of Education (through the BK21 Plus Project) of Korea, and the Center for Academic Computing at Kyung Hee University for computer resources.
Publisher Copyright:
© 2019 American Physical Society.
PY - 2019/2/28
Y1 - 2019/2/28
N2 - We consider a quantum dot coupled to both superconducting and spin-polarized electrodes, and we study the triad interplay of the Kondo effect, superconductivity, and ferromagnetism, any two of which compete with and suppress each other. We find that the interplay leads to a mixed-valence quantum phase transition, which for other typical systems is merely a crossover rather than a true transition. At the transition, the system changes from a spin-doublet to -singlet state. The singlet phase is adiabatically connected (through crossovers) to the so-called "charge Kondo state" and to the superconducting state. We analyze in detail the physical characteristics of different states, and we propose that the measurement of the cross-current correlation and the charge relaxation resistance can clearly distinguish between them.
AB - We consider a quantum dot coupled to both superconducting and spin-polarized electrodes, and we study the triad interplay of the Kondo effect, superconductivity, and ferromagnetism, any two of which compete with and suppress each other. We find that the interplay leads to a mixed-valence quantum phase transition, which for other typical systems is merely a crossover rather than a true transition. At the transition, the system changes from a spin-doublet to -singlet state. The singlet phase is adiabatically connected (through crossovers) to the so-called "charge Kondo state" and to the superconducting state. We analyze in detail the physical characteristics of different states, and we propose that the measurement of the cross-current correlation and the charge relaxation resistance can clearly distinguish between them.
UR - http://www.scopus.com/inward/record.url?scp=85062531241&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.99.075161
DO - 10.1103/PhysRevB.99.075161
M3 - Article
AN - SCOPUS:85062531241
VL - 99
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 1098-0121
IS - 7
M1 - 075161
ER -