Quantum-Limited Acoustoelectric Amplification in a Piezoelectric-2DEG Heterostructure

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Chatterjee, Eric, Soh, Daniel, Eichenfield, Matt
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866913120975323136
author Chatterjee, Eric
Soh, Daniel
Eichenfield, Matt
author_facet Chatterjee, Eric
Soh, Daniel
Eichenfield, Matt
contents We provide a quantum mechanical description of phonon amplification in a heterostructure consisting of a two-dimensional electron gas (2DEG) stacked on top of a piezoelectric material. An applied drift voltage effectively creates a population inversion in the momentum states of the 2DEG electrons, giving rise to spontaneous emission of phonons. Once an acoustic wave is launched, the pumped electrons release phonons via stimulated emission, returning to depleted ground states before being pumped back to the excited states. We show that whereas efficient amplification using a 1D electron gas requires the acoustic wavelength to roughly equal the average electron-electron spacing, a 2DEG enables efficient amplification for any wavelength greater than the average electron-electron spacing. We derive the imaginary and real parts of the 2DEG first-order acoustic susceptibility as functions of electronic drift velocity in specific limits and derive the gain per unit length for the signal and the quantum noise, with the gain matching the classical result in the short-electronic-lifetime (low-mobility) regime. Moreover, we analyze the gain clamping due to pump depletion and calculate the maximum achievable intensity. Our results provide a framework for designing novel acoustic devices including a quantum phononic laser and phase-insensitive quantum phononic amplifiers.
format Preprint
id arxiv_https___arxiv_org_abs_2510_09248
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Quantum-Limited Acoustoelectric Amplification in a Piezoelectric-2DEG Heterostructure
Chatterjee, Eric
Soh, Daniel
Eichenfield, Matt
Mesoscale and Nanoscale Physics
Quantum Physics
We provide a quantum mechanical description of phonon amplification in a heterostructure consisting of a two-dimensional electron gas (2DEG) stacked on top of a piezoelectric material. An applied drift voltage effectively creates a population inversion in the momentum states of the 2DEG electrons, giving rise to spontaneous emission of phonons. Once an acoustic wave is launched, the pumped electrons release phonons via stimulated emission, returning to depleted ground states before being pumped back to the excited states. We show that whereas efficient amplification using a 1D electron gas requires the acoustic wavelength to roughly equal the average electron-electron spacing, a 2DEG enables efficient amplification for any wavelength greater than the average electron-electron spacing. We derive the imaginary and real parts of the 2DEG first-order acoustic susceptibility as functions of electronic drift velocity in specific limits and derive the gain per unit length for the signal and the quantum noise, with the gain matching the classical result in the short-electronic-lifetime (low-mobility) regime. Moreover, we analyze the gain clamping due to pump depletion and calculate the maximum achievable intensity. Our results provide a framework for designing novel acoustic devices including a quantum phononic laser and phase-insensitive quantum phononic amplifiers.
title Quantum-Limited Acoustoelectric Amplification in a Piezoelectric-2DEG Heterostructure
topic Mesoscale and Nanoscale Physics
Quantum Physics
url https://arxiv.org/abs/2510.09248