SearcharxivSearch

arXiv · 2402.00273

Nonlinearity-Enhanced Continuous Microwave Detection Based on Stochastic Resonance

Abstract

In practical sensing tasks, noise is usually regarded as an obstruction to better performance and will degrade the sensitivity. Fortunately, \textit{stochastic resonance} (SR), a counterintuitive concept, can utilize noise to greatly enhance the detected signal amplitude. Although fundamentally important as a mechanism of weak signal amplification, and has been continually explored in geological, biological, and physical science, both theoretically and experimentally, SR has yet to be demonstrated in realistic sensing tasks. Here we develop a novel SR-based nonlinear sensor using a thermal ensemble of interacting Rydberg atoms. With the assistance of stochastic noise (either inherently in the system or added externally) and strong nonlinearity in the Rydberg ensembles, the signal encoded in a weak MW field is greatly enhanced (over 25 dB). Moreover, we show that the SR-based atomic sensor can achieve a better sensitivity in our system, which is over 6.6 dB compared to a heterodye atomic sensor. Our results show potential advantage of SR-based MW sensors in commercial or defense-related applications.

Explore related subjects

Keep this discovery

BibTeXRIS

Kang-Da Wu, Chongwu Xie, Chuan-Feng Li, Guang-Can Guo, Chang-Ling Zou, Guo-Yong Xiang. 2024-02-01. Nonlinearity-Enhanced Continuous Microwave Detection Based on Stochastic Resonance. https://doi.org/10.1126/sciadv.ado8130

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Delay-engineered dynamical phases in a programmable non-Markovian spin oscillator

Non-Markovian dynamics offer a new route towards engineering non-equilibrium matter, where memory and feedback act as programmable resources for controlling order in time. Here we report the realization of a non-Markovian spin oscillator in a hot vapour $^{129}$Xe-Cs co-magnetometer with programmable feedback delay and gain. By tuning these parameters, we observe a hierarchy of dynamical phases, including time-crystalline response, nonlinear bifurcations, and frequency-comb formation. The measured spectra and phase boundaries are captured by linear stability analysis of delayed Bloch equations, revealing these phenomena as different manifestations of the same memory-induced instability structure. These results establish time-delayed feedback as a powerful strategy for controlling non-equilibrium phases, enabling quantum sensing, frequency referencing, and synchronization within a single spin-based platform.

physics.atom-ph

Non-stick vacuum wall collisions with a laser-coolable molecule

Molecular species that are suitable for direct laser cooling are typically considered lost or destroyed if they collide with an ambient temperature vacuum wall. Here, we study surface collisions with aluminum monofluoride (AlF), a laser-coolable molecule that survives this process with unusually high probability. We detect the outgoing AlF molecules from a single wall collision via Doppler-sensitive laser-induced fluorescence spectroscopy, using incoming supersonic (pulsed) and thermochemical (continuous) molecular beams. The angular, velocity and rovibrational level distributions of the outgoing molecules show near-complete thermalisation to the wall in a single collision event. We determine an upper limit to the surface residence time of about 5$~\mu$s, and by monitoring the decay in density of pulses of molecules loaded into a small storage volume, we deduce the surface sticking probability for different materials. For a siloxane-coated metallic surface, the sticking probability of AlF is about 0.015, allowing us to accumulate molecules from the thermochemical source into an ambient temperature storage vessel at densities near $10^{8}~$cm$^{-3}$. This provides a route to compact, portable traps for neutral molecules.

physics.atom-ph

Kinetic modeling of molecular beam formation in a cryogenic buffer-gas cell

Cryogenic buffer-gas cells are widely used to produce cold molecular beams, but the microscopic dynamics governing beam formation remain challenging to model. Here we present fully kinetic simulations of a cryogenic buffer-gas cell using the Direct Simulation Monte Carlo method implemented in the PICLas framework, treating the buffer gas and ablated molecules within a single unified model. We capture characteristic features of cryogenic buffer-gas sources, including plume cooling, directed transport toward the aperture, and the formation of a slow molecular beam, while also resolving energy transfer from the hot ablation plume to the helium buffer gas that is inaccessible to existing approaches relying on the background-gas approximation. Our results demonstrate that fully kinetic simulations can provide detailed insights into buffer-gas cell dynamics and open a route toward a systematic optimization of such sources.

physics.atom-ph