The Kondo exciton: a quantum quench towards strong spin-reservoir correlations

Jan von Delft, LMU Munich

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 effct, can be read ośrom the absorption lineshape and understood in terms of the three fixed points of the single-impurity Anderson model. At low temperatures the lineshape 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. We will also report on recent experimental progress towards observing this physics.