Finite-temperature conductance signatures of quantum criticality in double quantum dots

Abstract

We study the linear conductance through a double-quantum-dot system consisting of an interacting dot in its Kondo regime and an effectively noninteracting dot connected in parallel to metallic leads. Signatures in the zero-bias conductance at temperatures T􏱁0 mark a pair of quantum 􏰂T=0􏰀 phase transitions between a Kondo-screened many-body ground state and non-Kondo ground states. Notably, the conductance features become more prominent with increasing T, which enhances the experimental prospects for accessing the quantum-critical region through tuning of gate voltages in a single device.