Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
Phys Rev Lett. 2011 Mar 11;106(10):107402. doi: 10.1103/PhysRevLett.106.107402. Epub 2011 Mar 9.
We study a quantum quench for a semiconductor quantum dot coupled to a fermionic reservoir, induced by the sudden creation of an exciton via optical absorption. The subsequent emergence of correlations between spin degrees of freedom of dot and reservoir, culminating in the Kondo effect, can be read off from the absorption line shape and understood in terms of the three fixed points of the single-impurity Anderson model. At low temperatures the line shape is dominated by a power-law singularity, with an exponent that depends on gate voltage and, in a universal, asymmetric fashion, on magnetic field, indicative of a tunable Anderson orthogonality catastrophe.
我们研究了半导体量子点与费米子储库耦合的量子淬火，这是通过光吸收突然产生激子引起的。随后，在库中自旋自由度之间出现相关性，最终导致了近藤效应，可以从吸收线形状中读出，并根据单杂质安德森模型的三个不动点来理解。在低温下，线形状主要由幂律奇点主导，其指数取决于栅极电压，并以通用的、不对称的方式取决于磁场，这表明可以调节安德森正交性灾难。
