English
Related papers

Related papers: An Extreme Metastable Model for Quantum Measuremen…

200 papers

The simultaneous estimation of multiple unknown parameters is the most general scenario in quantum sensing. Quantum multi-parameter estimation theory provides fundamental bounds on the achievable precision of simultaneous estimation.…

Quantum Physics · Physics 2025-12-02 Yaoling Yang , Victor Montenegro , Abolfazl Bayat

The reduced density matrix that characterises the state of an open quantum system is a projection from the full density matrix of the quantum system and its environment, and there are many full density matrices consistent with a given…

Quantum Physics · Physics 2024-11-28 Claudia L. Clarke , Ian J. Ford

We study experimentally and numerically the equilibrium density profiles of a trapped two-dimensional $^{87}$Rb Bose gas, and investigate the equation of state of the homogeneous system using the local density approximation. We find a clear…

In this article, we propose a novel method for sampling potential functions based on noisy observation data of a finite number of observables in quantum canonical ensembles, which leads to the accurate sampling of a wide class of test…

Numerical Analysis · Mathematics 2020-04-08 Ziheng Chen , Zhennan Zhou

The liquid-vapor transition is a classic example of a discontinuous (first-order) phase transition. Such transitions underlie many phenomena in cosmology, nuclear and particle physics, and condensed-matter physics. They give rise to…

We study the factorised steady state of a general class of mass transport models in which mass, a conserved quantity, is transferred stochastically between sites. Condensation in such models is exhibited when above a critical mass density…

Statistical Mechanics · Physics 2008-09-25 Martin R. Evans , Satya N. Majumdar

Coherent coupling between a large number of qubits is the goal for scalable approaches to solid state quantum information processing. Prototype systems can be characterized by spectroscopic techniques. Here, we use pulsed-continuous wave…

Mesoscale and Nanoscale Physics · Physics 2011-04-01 M. Ziaur Rahman Khan , D. G. Hasko , M. S. M. Saifullah , M. E. Welland

A new entanglement measure, the multiple entropy measures (MEMS), is proposed to quantify quantum entanglement of multi-partite quantum state. The MEMS is vector-like with $m=[N/2]$, the integer part of $N/2$, components: $[S_1, S_2,...,…

Quantum Physics · Physics 2007-06-23 Dan Liu , Xin Zhao , Gui Lu Long

The dynamics of quantum degenerate two-dimensional dipolar excitons confined in electrostatic traps is analyzed and compared to recent experiments. The model results stress the importance of artificial trapping for achieving and sustaining…

Other Condensed Matter · Physics 2009-11-11 Ronen Rapaport , Gang Chen , Steven Simon

Simultaneous measurement of several noncommuting observables is modeled by using semigroups of completely positive maps on an algebra with a non-trivial center. The resulting piecewise-deterministic dynamics leads to chaos and to nonlinear…

Quantum Physics · Physics 2007-05-23 Arkadiusz Jadczyk

The resources needed to conventionally characterize a quantum system are overwhelmingly large for high- dimensional systems. This obstacle may be overcome by abandoning traditional cornerstones of quantum measurement, such as general…

Quantum Physics · Physics 2016-05-17 Gregory A. Howland , Samuel H. Knarr , James Schneeloch , Daniel J. Lum , John C. Howell

Quantum-enhanced measurements exploit quantum mechanical effects to provide ultra-precise estimates of physical variables for use in advanced technologies, such as frequency calibration of atomic clocks, gravitational waves detection, and…

Quantum Physics · Physics 2014-07-28 J. Calsamiglia , B. Gendra , R. Munoz-Tapia , E. Bagan

We describe a method for precise estimation of the polarization of a mesoscopic spin ensemble by using its coupling to a single two-level system. Our approach requires a minimal number of measurements on the two-level system for a given…

Quantum Physics · Physics 2009-11-11 G. Giedke , J. M. Taylor , D. D'Alessandro , M. D. Lukin , A. Imamoglu

We present a new approach to the study of equilibrium properties in many-body quantum physics. Our method takes inspiration from Density Matrix Quantum Monte Carlo and incorporates new crucial features. First of all, the dynamics is…

Quantum Physics · Physics 2022-01-06 Romain Chessex , Massimo Borrelli , Hans Christian Öttinger

In the quantum Zeno effect, quantum measurements can block the coherent oscillation of a two level system by freezing its state to one of the measurement eigenstates. The effect is conventionally controlled by the measurement frequency.…

Quantum Physics · Physics 2020-10-06 Kyrylo Snizhko , Parveen Kumar , Alessandro Romito

We explore the measurement problem in the entropic dynamics approach to quantum theory. The dual modes of quantum evolution---either continuous unitary evolution or abrupt wave function collapse during measurement---are unified by virtue of…

Quantum Physics · Physics 2015-05-30 David T. Johnson , Ariel Caticha

The evolution of a quantum system subject to measurements can be described by stochastic quantum trajectories of pure states. Instead, the ensemble average over trajectories is a mixed state evolving via a master equation. Both descriptions…

Quantum Physics · Physics 2024-02-22 Christian Carisch , Alessandro Romito , Oded Zilberberg

The standard quantum formalism introduced at the undergraduate level treats measurement as an instantaneous collapse. In reality however, no physical process can occur over a truly infinitesimal time interval. A more subtle investigation of…

Quantum Physics · Physics 2020-04-22 Leigh S. Martin

This paper presents a simple model for repeated measurement of a quantum system: the evolution of a free particle, simulated by discretising the particle's position. This model is easily simulated by computer and provides a useful arena to…

Quantum Physics · Physics 2009-11-06 David Wallace

Quantum benchmarks are routinely used to validate the experimental demonstration of quantum information protocols. Many relevant protocols, however, involve an infinite set of input states, of which only a finite subset can be used to test…

Quantum Physics · Physics 2021-09-28 Ge Bai , Giulio Chiribella