Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Bulletin of the American Physical Society

Classical-to-quantum transition of exceptional points induced by thermal noise

Adam Miranowicz, Ravindra W. Chhajlany, Fabrizio Minganti, Ievgen I. Arkhipov, Franco Nori

Published Mar 15, 2021• 0 citations
OpenAlex

Related papers

Interplay of Quantum and Classical Fluctuations Near Quantum Critical Points

M. A. Contínentino

arXiv:1108.0651•Brazilian Journal of Physics•Jul 16, 2011•8 citations

Universal Phenomenology at Critical Exceptional Points of Nonequilibrium O ( N ) Models

Carl Philipp Zelle, Romain Daviet, Achim Rosch +1 more

In thermal equilibrium the dynamics of phase transitions is largely controlled by fluctuation-dissipation relations: On the one hand, friction suppresses fluctuations, while on the other hand, the thermal noise is proportional to friction constants. Out of equilibrium, this balance dissolves and one can have situations where friction vanishes due to antidamping in the presence of a finite noise level. We study a wide class of O ( N ) field theories where this situation is realized at a phase transition, which we identify as a critical exceptional point. In the ordered phase, antidamping induces a continuous limit cycle rotation of the order parameter with an enhanced number of 2 N − 3 Goldstone modes. Close to the critical exceptional point, however, fluctuations diverge so strongly due to the suppression of friction that in dimensions d < 4 they universally either destroy a preexisting static order or give rise to a fluctuation-induced first-order transition. This is demonstrated within a full resummation of loop corrections via Dyson-Schwinger equations for N = 2 , and a generalization for arbitrary N , which can be solved in the long wavelength limit. We show that in order to realize this physics it is not necessary to drive a system far out of equilibrium: Using the peculiar protection of Goldstone modes, the transition from an x y magnet to a ferrimagnet is governed by an exceptional critical point once weakly perturbed away from thermal equilibrium. Published by the American Physical Society 2024

arXiv:2304.09207•Physical Review X•Jun 26, 2024•30 citations

No Fundamental Sensing Advantage from Exceptional Point Sensors

Hudson A. Loughlin, Vivishek Sudhir

We present a theory of quantum noise in exceptional point sensors. We find that these sensors have no sensing advantage relative to traditional sensors limited by fundamental quantum or thermal noise.

Frontiers in Optics•Jan 1, 2024•0 citations

Quantum critical states and phase transitions in the presence of non-equilibrium noise

Emanuele G. Dalla Torre, Eugene Demler, Thierry Giamarchi +1 more

arXiv:0908.0868•Nature Physics•Aug 29, 2010•164 citations

Fluctuation-Induced Quantum Phase Transitions

World Scientific lecture notes in physics•Jan 1, 2001•0 citations

Exceptional-Point Sensors Offer No Fundamental Signal-to-Noise Ratio Enhancement

Hudson A. Loughlin, Vivishek Sudhir

Exceptional-point (EP) sensors exhibit a square-root resonant frequency bifurcation in response to external perturbations, making them appear attractive for sensing applications. However, there is an open debate as to whether or not this sensitivity advantage is negated by additional noise in the system. We settle this debate by showing that increased fundamental noises of quantum and thermal origin in EP sensors, and in particular self-excited (or PT-symmetric) EP sensors, negate the sensitivity benefit. Accordingly, EP sensing schemes are only beneficial either with further quantum enhancement or if compared to sensors limited by technical noise. As many modern sensors are limited by technical noise, EP sensors may still find practical uses despite their lack of a fundamental advantage. Alternatively, we propose a quantum-enhanced EP sensor that achieves a sensing advantage even when limited by quantum or thermal fluctuations.

arXiv:2401.04825•Physical Review Letters•Jun 13, 2024•77 citations
In thermal equilibrium the dynamics of phase transitions is largely controlled by fluctuation-dissipation relations: On the one hand, friction suppresses fluctuations, while on the other hand, the thermal noise is proportional to friction constants. Out of equilibrium, this balance dissolves and one can have situations where friction vanishes due to antidamping in the presence of a finite noise level. We study a wide class of O ( N ) field theories where this situation is realized at a phase transition, which we identify as a critical exceptional point. In the ordered phase, antidamping induces a continuous limit cycle rotation of the order parameter with an enhanced number of 2 N − 3 Goldstone modes. Close to the critical exceptional point, however, fluctuations diverge so strongly due to the suppression of friction that in dimensions d < 4 they universally either destroy a preexisting static order or give rise to a fluctuation-induced first-order transition. This is demonstrated within a full resummation of loop corrections via Dyson-Schwinger equations for N = 2 , and a generalization for arbitrary N , which can be solved in the long wavelength limit. We show that in order to realize this physics it is not necessary to drive a system far out of equilibrium: Using the peculiar protection of Goldstone modes, the transition from an x y magnet to a ferrimagnet is governed by an exceptional critical point once weakly perturbed away from thermal equilibrium. Published by the American Physical Society 2024
Exceptional-point (EP) sensors exhibit a square-root resonant frequency bifurcation in response to external perturbations, making them appear attractive for sensing applications. However, there is an open debate as to whether or not this sensitivity advantage is negated by additional noise in the system. We settle this debate by showing that increased fundamental noises of quantum and thermal origin in EP sensors, and in particular self-excited (or PT-symmetric) EP sensors, negate the sensitivity benefit. Accordingly, EP sensing schemes are only beneficial either with further quantum enhancement or if compared to sensors limited by technical noise. As many modern sensors are limited by technical noise, EP sensors may still find practical uses despite their lack of a fundamental advantage. Alternatively, we propose a quantum-enhanced EP sensor that achieves a sensing advantage even when limited by quantum or thermal fluctuations.