Single-electron detection in a high-purity Ge device
Abstract
High-purity germanium (HPGe) detectors are among the most powerful instruments for gamma ray spectroscopy, combining exceptional energy resolution with large active volumes. Although they operate close to the fundamental resolution limit at high energies, their performance at very low energies has long been limited by electronic noise, restricting detection thresholds to above approximately 30 electron-hole pairs (∼100 eV). Here we introduce a cryogenic HPGe detector architecture that achieves single electron-hole pair sensitivity by calorimetrically measuring ionization at temperatures near 20 mK. The device integrates a NbSi transition-edge sensor into a point-contact-inspired geometry, concentrating athermal phonon energy generated during charge drift and enabling eV-scale sensitivity ultimately set by the semiconductor band gap. Beyond single-charge detection, the device rejects the low-energy excess background that limits existing cryogenic low-threshold technologies, establishing a pathway towards discrimination between electron- and nuclear-recoil events below 100 eV. These advances open a route towards next-generation detectors for direct dark matter searches, coherent elastic neutrino-nucleus scattering, and nuclear reactor monitoring for non-proliferation applications.
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BibTeX
@misc{armatol2026singleelectron,
title = {{Single-electron detection in a high-purity Ge device}},
author = {Antoine Armatol and Corinne Augier and Laurent Bergé and Julien Billard and Harvey Birch and Juliette Blé and Clarence Chang and Yen-Yung Chang and Luke Chaplinsky and Gordon Cline and Alec Cochard and Ion Cojocari and Jules Colas and Simon Connolly and Maryvonne de Jesus and Pierre de Marcillac and Kamil Dwinger and Romain Faure and Simon Fiorucci and Maurice Garcia-Sciveres and Jules Gascon and Ryan Gibbons and Gil Gilchriese and Cloé Girard-Carillo and Wei Guo and Leila Haegel and Scott Haselschwardt and Scott Hertel and Tyler Horoho and Keith Hunter and Leslie Juigne and Alexandre Juillard and Alex Kavner and Jacob Lamblin and Tatiana Le-Bellec and Junsong Lin and Rupak Mahapatra and Stefanos Marnieros and Claire Marrache-Kikuchi and Nicolas Martini and Will Matava and Daniel Mckinsey and Connor Mclaughlin and Johann Menu and Knut Moraa and Valentina Novati and Emiliano Olivieri and Björn Penning and Mark Platt and Denys Poda and Matt Pyle and Yinghe Qi and Rafsan Rabbi and Ivar Rydstrom and Bernard Sadoulet and Silvia Scorza and Bruno Serfass and Peter Sorensen and Gabrielle Soum-Sidikov and Samara Steinfeld},
howpublished = {HAL},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.23110},
eprint = {2609.23110},
archivePrefix = {arXiv},
url = {https://hal.science/hal-05763149v1},
}
RIS
TY - UNPB
TI - Single-electron detection in a high-purity Ge device
AU - Antoine Armatol
AU - Corinne Augier
AU - Laurent Bergé
AU - Julien Billard
AU - Harvey Birch
AU - Juliette Blé
AU - Clarence Chang
AU - Yen-Yung Chang
AU - Luke Chaplinsky
AU - Gordon Cline
AU - Alec Cochard
AU - Ion Cojocari
AU - Jules Colas
AU - Simon Connolly
AU - Maryvonne de Jesus
AU - Pierre de Marcillac
AU - Kamil Dwinger
AU - Romain Faure
AU - Simon Fiorucci
AU - Maurice Garcia-Sciveres
AU - Jules Gascon
AU - Ryan Gibbons
AU - Gil Gilchriese
AU - Cloé Girard-Carillo
AU - Wei Guo
AU - Leila Haegel
AU - Scott Haselschwardt
AU - Scott Hertel
AU - Tyler Horoho
AU - Keith Hunter
AU - Leslie Juigne
AU - Alexandre Juillard
AU - Alex Kavner
AU - Jacob Lamblin
AU - Tatiana Le-Bellec
AU - Junsong Lin
AU - Rupak Mahapatra
AU - Stefanos Marnieros
AU - Claire Marrache-Kikuchi
AU - Nicolas Martini
AU - Will Matava
AU - Daniel Mckinsey
AU - Connor Mclaughlin
AU - Johann Menu
AU - Knut Moraa
AU - Valentina Novati
AU - Emiliano Olivieri
AU - Björn Penning
AU - Mark Platt
AU - Denys Poda
AU - Matt Pyle
AU - Yinghe Qi
AU - Rafsan Rabbi
AU - Ivar Rydstrom
AU - Bernard Sadoulet
AU - Silvia Scorza
AU - Bruno Serfass
AU - Peter Sorensen
AU - Gabrielle Soum-Sidikov
AU - Samara Steinfeld
PY - 2026
DA - 2026/09/19
PB - HAL
DO - 10.48550/arxiv.2609.23110
UR - https://hal.science/hal-05763149v1
AB - High-purity germanium (HPGe) detectors are among the most powerful instruments for gamma ray spectroscopy, combining exceptional energy resolution with large active volumes. Although they operate close to the fundamental resolution limit at high energies, their performance at very low energies has long been limited by electronic noise, restricting detection thresholds to above approximately 30 electron-hole pairs (∼100 eV). Here we introduce a cryogenic HPGe detector architecture that achieves single electron-hole pair sensitivity by calorimetrically measuring ionization at temperatures near 20 mK. The device integrates a NbSi transition-edge sensor into a point-contact-inspired geometry, concentrating athermal phonon energy generated during charge drift and enabling eV-scale sensitivity ultimately set by the semiconductor band gap. Beyond single-charge detection, the device rejects the low-energy excess background that limits existing cryogenic low-threshold technologies, establishing a pathway towards discrimination between electron- and nuclear-recoil events below 100 eV. These advances open a route towards next-generation detectors for direct dark matter searches, coherent elastic neutrino-nucleus scattering, and nuclear reactor monitoring for non-proliferation applications.
ER -