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Yugang Ren

Publications and source records attributed to Yugang Ren.

5 recordsLinked to original sources

A Levitated Random Telegraph Noise Spectrometer

Random Telegraph Noise is a ubiquitous process manifesting across technology and the natural world. It is characterized by random jumps between two distinct states with Poissonian waiting times, and is the origin of 1/f noise. Understanding and characterizing this noise is critical for the reliable operation of micro-, nano- and quantum-technologies. In this work we probe random telegraph noise using a levitated microparticle sensor whose dynamics are driven almost entirely by this non-white source of noise. We observe a startling resonant behaviour, characterized by a thousand-fold increase in the underdamped sensor's position fluctuations, enabling us to measure the spectral properties of the noise over six decades of timescale. This work not only provides a unique way to probe random telegraph noise, but also demonstrates a platform for studying non-equilibrium stochastic dynamics in the presence of realistic non-white noise, with applications from biology to social behaviour.

physics.ins-det

Talking with a ghost: semi-virtual coupled levitated oscillators

Mesoscopic particles levitated by optical, electrical or magnetic fields act as mechanical oscillators with a range of surprising properties, such as tuneable oscillation frequencies, access to rotational motion, and remarkable quality factors. Coupled levitated particles display rich dynamics and non-reciprocal interactions, with applications in sensing and the exploration of non-equilibrium and quantum physics. In this work, we present a single levitated particle displaying coupled-oscillator dynamics by generating an interaction with a virtual or ``ghost'' particle. This ghost levitated particle is simulated on an analogue computer, and its properties can thus be dynamically varied. Our work represents a new angle on measurement-based bath engineering and physical simulation and, in the future, could lead to the generation of novel cooling mechanisms and complex physical simulation.

physics.ins-det

Extreme-temperature single-particle heat engine

There are many exotic thermodynamic processes that are hard to study in nature. Here, we synthesize a structured environment to explore the extremes of thermodynamics. We present an engine running at extreme temperatures of above ten Mega-Kelvin. Our underdamped engine is realised by electrically levitating and controlling a charged microparticle in vacuum. Giant fluctuations are observed in the engine's heat exchange with the environment, while its efficiency shows stochastic events where more work is performed by the engine than heat consumed. Moreover, the non-uniformity of the synthetic environment leads to the particle experiencing position dependent diffusion, a critical phenomenon in microscale biological processes. We theoretically account for the effects of multiplicative noise and find excellent agreement with the observed behavior.

cond-mat.stat-mech

Neuromorphic detection and cooling of microparticles in arrays

Micro-objects levitated in a vacuum are an exciting platform for precision sensing due to their low dissipation motion and the potential for control at the quantum level. Arrays of such sensors would offer increased sensitivity, directionality, and in the quantum regime the potential to exploit correlation and entanglement. We use neuromorphic detection via a single event based camera to record the motion of an array of levitated microspheres. We present a scalable method for arbitrary multiparticle tracking and control by implementing real-time feedback to {simultaneously cool the motion of three uncoupled microscale objects

physics.ins-det

Event-Based Imaging of Levitated Microparticles

Event-based imaging is a neurmorphic detection technique whereby an array of pixels detects a positive or negative change in light intensity at each pixel, and is hence particularly well suited to detecting motion. As compared to standard camera technology, an event-based camera reduces redundancy by not detecting regions of the image where there is no motion, allowing increased frame-rates without compromising on field-of-view. Here, we apply event-based imaging to detect the motion of a microparticle levitated under vacuum conditions, which greatly facilitates the study of nanothermodynamics and enables the independent detection and control of arrays of many particles.

physics.ins-det