Klees R L, Rastelli G, Cuevas J C, Belzig W
Fachbereich Physik, Universität Konstanz, D-78457 Konstanz, Germany.
Zukunftskolleg, Universität Konstanz, D-78457 Konstanz, Germany.
Phys Rev Lett. 2020 May 15;124(19):197002. doi: 10.1103/PhysRevLett.124.197002.
Quantization effects due to topological invariants such as Chern numbers have become very relevant in many systems, yet key quantities such as the quantum geometric tensor providing local information about quantum states remain experimentally difficult to access. Recently, it has been shown that multiterminal Josephson junctions constitute an ideal platform to synthesize topological systems in a controlled manner. We theoretically study properties of Andreev states in topological Josephson matter and demonstrate that the quantum geometric tensor of Andreev states can be extracted by synthetically polarized microwaves. The oscillator strength of the absorption rates provides direct evidence of topological quantum properties of the Andreev states.
由于诸如陈数等拓扑不变量引起的量子化效应在许多系统中变得非常重要，然而，诸如提供量子态局部信息的量子几何张量等关键量在实验上仍然难以获取。最近，已经表明多端约瑟夫森结构成了一个以可控方式合成拓扑系统的理想平台。我们从理论上研究了拓扑约瑟夫森物质中安德列夫态的性质，并证明了安德列夫态的量子几何张量可以通过合成极化微波来提取。吸收率的振子强度为安德列夫态的拓扑量子性质提供了直接证据。
