Department of Physics, Korea Advanced Institute of Science and Technology, Daejeon 34141, Korea.
Physics Department, Arnold Sommerfeld Center for Theoretical Physics, and Center for NanoScience, Ludwig-Maximilians-Universität, Theresienstraße 37, D-80333 München, Germany.
Phys Rev Lett. 2018 Apr 6;120(14):146801. doi: 10.1103/PhysRevLett.120.146801.
Quantum entanglement between an impurity spin and electrons nearby is a key property of the single-channel Kondo effects. We show that the entanglement can be detected by measuring electron conductance through a double quantum dot in an orbital Kondo regime. We derive a relation between the entanglement and the conductance, when the SU(2) spin symmetry of the regime is weakly broken. The relation reflects the universal form of many-body states near the Kondo fixed point. Using it, the spatial distribution of the entanglement-hence, the Kondo cloud-can be detected, with breaking of the symmetry spatially nonuniformly by electrical means.
杂质自旋与附近电子之间的量子纠缠是单通道科顿效应的关键性质。我们表明，通过在轨道科顿区的双量子点测量电子电导，可以检测到纠缠。当该区域的 SU(2)自旋对称性被弱破坏时，我们推导出了纠缠与电导之间的关系。该关系反映了科顿临界点附近多体态的普遍形式。利用这个关系，可以通过电学手段在空间上非均匀地破坏对称性，从而检测到纠缠的空间分布——即科顿云。
