題目：Topological Majorana Two-Channel Kondo Effect
報告人：鮑志強 博士（美國德克薩斯大學達拉斯分校物理系） 
時  間：2018年4月12日(周四)上午10:00
地  點：北京理工大學中心教學樓610
摘要：

The Kondo e?ect is one of the most fundamental problems in condensed matter physics. Not only does it reveal how delocalized electrons interact with a local degeneracy, but it also exempli?es scaling and universality in strongly correlated systems that are driven by weak coupling instabilities. In the 1 channel Kondo (1CK) effect, a twofold degeneracy such as a local spin-1/2 impurity is antiferromagnetically coupled to a reservoir of conduction electrons and the ground state is a Fermi liquid. In the more tantalizing 2CK effect, two independent reservoirs compete to screen the spin and thus overscreen it, leading to non-Fermi-liquid quantum criticality. The delicate 2CK effect is unlikely to occur, as any channel asymmetry drives the system toward the 1CK effect in the more strongly coupled channel. Realizing the 2CK effect without fine-tuning the channel symmetry has long been an unrealized dream. In this work, we propose a new device named Majorana transistor, which is a time-reversal-invariant topological superconductor (TSC) grounded by a capacitor and tunnel-coupled to left and right leads. By using the standard Schrieffer-Wolf transformation and perturbative renormalization group method, we demonstrate the realization of a topologically protected, channel-symmetric, two-channel Kondo effect without fine-tuning in the Majorana transistor. We also examine the transport anomaly of the Majorana transistor. Whereas the nonlocal teleportation vanishes, a lead present at one end telecontrols the universal transport through the other end.

簡歷：
鮑志強博士，目前在美國德克薩斯大學達拉斯分校物理系做博士后，主要研究方向包括量子多體與Kondo效應，凝聚態物理中的新奇量子現象，量子輸運等。2015年博士畢業于中國科學院物理研究所，2012年碩士畢業于北京大學物理學院，2008年本科畢業于天津大學。

聯系方式：物理學院辦公室 （15810823175）
邀請人：劉鋮鋮
網    址：http://physics.bit.edu.cn/