Majorana signature in dissipation via chiral topological superconductors
일 시 : 2021년 03월 31일 수요일 16:00
연 사 : 이 민 철 교수 (경희대학교 응용물리학과)
장 소 : 온라인 줌 진행( https://us02web.zoom.us/j/81366062027, 회의 ID: 813 6606 2027 )
HOST : 신 상 진 교수님
초 록
This talk presents the studies on dissipation in a topological resistor–capacitor (RC) circuit consisting of a quantum dot coupled to a Majorana edge mode formed around a chiral topological superconductor. The dissipation is measured in terms of the relaxation resistance RqR_q whose frequency dependence is investigated in both the linear and non-linear response regimes. The nature of Majorana fermions, which are their own anti-particles, is found to lead to substantially enhanced relaxation resistance. Furthermore, a destructive interference completely suppresses the low-frequency relaxation resistance so that Rq∝Ω2R_q \propto \Omega^2 where Ω\Omega is the frequency of the ac driving on the dot. Interestingly, when the time-dependent dot level crosses the Fermi level, Rq∝Ω-1/3R_q \propto \Omega^{-1/3} diverges as Ω→0\Omega \to 0, exhibiting a universal scaling law for the dissipative part of the ac power. The latter is attributed to the δ-peak in the dot density of states due to a uncoupled dot Majorana mode at the dot resonance condition.