Quantum Noise from a Bohmian perspective: fundamental understanding and practical computation in electron devices

TL;DR

This paper explores quantum noise in electron transport using Bohmian mechanics, providing both fundamental insights and practical computational methods demonstrated through simulations of a resonant tunneling diode.

Contribution

It introduces a Bohmian mechanics-based approach to understand and compute quantum noise in electron devices, linking theory with practical simulation techniques.

Findings

Bohmian trajectories effectively model quantum shot noise.

Simulations reveal frequency-dependent noise characteristics.

The BITLLES simulator demonstrates practical computation of quantum noise.

Abstract

In the literature, the study of electron transport in quantum devices is mainly devoted to DC properties. The fluctuations of the electrical current around these DC values, the so-called quantum noise, are much less analyzed. The computation of quantum noise is intrinsically linked (by temporal correlations) to our ability to understand/compute the time-evolution of a quantum system that is measured several times. There are several quantum theories that provide different (but empirically equivalent) ways of understanding/computing the perturbation of the wave function when it is measured. In this work, quantum noise associated to an electron impinging upon a semitransparent barrier is explained using Bohmian mechanics (which deals with wave functions and point-like particles). From this result, the fundamental understanding and practical computation of quantum noise with Bohmian trajectories are discussed. Numerical simulations of low and high frequency features of quantum shot noise in a resonant tunneling diode are presented (through the BITLLES simulator), showing the usefulness of the Bohmian approach.