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

TL;DR

This paper investigates how finite-temperature conductance measurements in a double quantum dot system reveal signatures of quantum criticality, highlighting temperature effects on phase transition signatures and experimental detection.

Contribution

It introduces a detailed analysis of finite-temperature conductance signatures associated with quantum phase transitions in a double quantum dot system, emphasizing experimental relevance.

Findings

Conductance features become more prominent with increasing temperature.

Zero-bias conductance signatures mark quantum phase transitions.

Tuning gate voltages can access the quantum-critical region.

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.