The problem of "macroscopic charge quantization" in single-electron devices

TL;DR

This paper investigates macroscopic charge quantization in single-electron devices, revealing deep connections to quantum Hall effects and introducing a comprehensive response theory to understand their behavior across different coupling regimes.

Contribution

It develops a new response theory for SETs based on AES theory, linking charge quantization to topological features and the quantum Hall effect, and analyzes behavior from weak to strong coupling regimes.

Findings

Charge quantization in SETs is analogous to quantum Hall effect.

A unifying scaling diagram of SET behavior is established.

Topological features of the theta-angle are identified in SETs.

Abstract

In a recent Letter by the authors [I.S. Burmistrov and A.M.M. Pruisken, Phys. Rev. Lett. 101, 056801 (2008)] it was shown that single-electron devices (single electron transistor or SET) display "macroscopic charge quantization" which is completely analogous to the quantum Hall effect observed on very different electron systems. In this investigation we present more detail on these new findings. Based on the Ambegaokar-Eckern-Schoen (AES) theory of the Coulomb blockade we introduce a general response theory that probes the sensitivity of SET to changes in the boundary conditions. This response theory defines a new set of physical observables and we establish the contact with the standard results obtained from ordinary linear response theory. The response parameters generally define the renormalization behavior of the SET in the entire regime from weak coupling with large values of the tunneling conductance all the way down to the strong coupling phase where the system displays the Coulomb blockade. We introduce a general criterion for charge quantization that is analogous to the Thouless criterion for Anderson localization. We present the results of detailed computations on the weak coupling side of the theory, i.e. both perturbative and non-perturbative (instantons). Based on an effective theory in terms of quantum spins we study the quantum critical behavior of the AES model on the strong coupling side. Consequently, a unifying scaling diagram of the SET is obtained. This diagram displays all the super universal topological features of the theta-angle concept that previously arose in the theory of the quantum Hall effect.