Quantum Zeno Manipulation of Quantum Dots

TL;DR

This paper explores how the quantum Zeno effect can be used to control electron tunneling in quantum dots, considering practical conditions and the potential for both inhibiting and accelerating quantum evolution.

Contribution

It analyzes the feasibility of applying the quantum Zeno effect to quantum dots with continuum reservoirs, including conditions that facilitate or hinder this control mechanism.

Findings

Quantum Zeno effect can inhibit electron tunneling under specific conditions.

Flat band or slow group velocity can enhance measurement repetition rate.

Anti-Zeno effect can accelerate quantum evolution in quantum dots.

Abstract

We investigate whether and how the quantum Zeno effect, i.e., the inhibition of quantum evolution by frequent measurements, can be employed to isolate a quantum dot from its surrounding electron reservoir. In contrast to the often studied case of tunneling between discrete levels, we consider the tunnelling of an electron from a continuum reservoir to a discrete level in the dot. Realizing the quantum Zeno effect in this scenario can be much harder because the measurements should be repeated before the wave packet of the hole left behind in the reservoir moves away from the vicinity of the dot. Thus, the required repetition rate could be lowered by having a flat band (with a slow group velocity) in resonance with the dot or a sufficiently small Fermi velocity or a strong external magnetic field. We also consider the anti-Zeno effect, i.e., how measurements can accelerate or enable quantum evolution.