The Josephson junction is typically tuned by a magnetic field or electrostatic gate to realize a superconducting(SC)transistor,which manipulates the supercurrent in integrated SC circuits.Here,we propose a theoretical...The Josephson junction is typically tuned by a magnetic field or electrostatic gate to realize a superconducting(SC)transistor,which manipulates the supercurrent in integrated SC circuits.Here,we propose a theoretical scheme for a light-controlled SC transistor,which is composed of two superconductor leads weakly linked by a coherent light-driven quantum dot.We discover a Josephson-like relation for the supercurrent I=I(Φ)sinΦsc,where both the supercurrent phaseΦand magnitude Iccan be completely controlled by the phase,intensity,and detuning of the driving light.Additionally,the supercurrent magnitude displays a Fano profile with the increase of the driving light intensity,which is understood by comparing the level splitting of the quantum dot under light driving with the SC gap.Moreover,when two such SC transistors form a loop,they constitute a light-controlled SC quantum interference device(SQUID).Such a light-controlled SQUID can demonstrate the Josephson diode effect,and the optimized non-reciprocal efficiency achieves up to 54%,surpassing the maximum record reported in recent literature.Thus,our scheme delivers a promising platform for performing diverse and flexible manipulations in SC circuits.展开更多
基金supported by NSF of China(Grant Nos.12088101 and 11905007)NSAF(Grants Nos.U1930403 and U1930402)。
文摘The Josephson junction is typically tuned by a magnetic field or electrostatic gate to realize a superconducting(SC)transistor,which manipulates the supercurrent in integrated SC circuits.Here,we propose a theoretical scheme for a light-controlled SC transistor,which is composed of two superconductor leads weakly linked by a coherent light-driven quantum dot.We discover a Josephson-like relation for the supercurrent I=I(Φ)sinΦsc,where both the supercurrent phaseΦand magnitude Iccan be completely controlled by the phase,intensity,and detuning of the driving light.Additionally,the supercurrent magnitude displays a Fano profile with the increase of the driving light intensity,which is understood by comparing the level splitting of the quantum dot under light driving with the SC gap.Moreover,when two such SC transistors form a loop,they constitute a light-controlled SC quantum interference device(SQUID).Such a light-controlled SQUID can demonstrate the Josephson diode effect,and the optimized non-reciprocal efficiency achieves up to 54%,surpassing the maximum record reported in recent literature.Thus,our scheme delivers a promising platform for performing diverse and flexible manipulations in SC circuits.
