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Quantum magnetic field sensing is an important technology for material science and biology. Although experimental imperfections affect the sensitivity, repetitions of the measurements decrease the estimation uncertainty by a square root of…

Quantum Physics · Physics 2021-03-29 Alisa Shimada , Hideaki Hakoshima , Suguru Endo , Kaoru Yamamoto , Yuichiro Matsuzaki

The quantum Zeno effect is usually thought to require infinitely frequent and perfect projective measurements to freeze the dynamics of quantum states. We show that perfect freezing of quantum states can also be achieved by more realistic…

Quantum Physics · Physics 2015-02-13 David Layden , Eduardo Martin-Martinez , Achim Kempf

Technologies for manipulating single atoms have advanced drastically in the past decades. Due to their excellent controllability of internal states, atoms serve as one of the ideal platforms as quantum systems. One major research direction…

Atomic Physics · Physics 2026-01-01 Akio Kawasaki

A tenet of time-resolved spectroscopy is -faster laser pulses for shorter timescales- . Here we suggest turning this paradigm around, and slow down the system dynamics via repeated measurements, to do spectroscopy on longer timescales. This…

Quantum metrology utilizes entanglement for improving the sensitivity of measurements. Up to now the focus has been on the measurement of just one out of two non-commuting observables. Here we demonstrate a laser interferometer that…

Short pulses from mode-locked lasers can produce background-free atomic fluorescence by allowing temporal separation of the prompt incidental scatter from the subsequent atomic emission. We use this to improve quantum state detection of…

Atomic Physics · Physics 2020-08-26 Conrad Roman , Anthony Ransford , Michael Ip , Wesley C. Campbell

Using the inherent timing stability of pulses from a mode-locked laser, we have precisely measured the cesium $6P_{3/2}$ excited state lifetime. An initial pump pulse excites cesium atoms in two counter-propagating atomic beams to the…

In this Letter, the quantum correlation measurement technique as a method of power noise monitoring is investigated. Its principal idea of correlating two photodetector signals is introduced and contrasted to the conventional approach,…

Optics · Physics 2022-03-02 Jasper Robert Venneberg , Benno Willke

Within quantum information, many methods have been proposed to avoid or correct the deleterious effects of the environment on a system of interest. In this work, expanding on our earlier paper [G. A. Paz-Silva et al., Phys. Rev. Lett. 108,…

Quantum Physics · Physics 2014-02-26 Jason M. Dominy , Gerardo A. Paz-Silva , A. T. Rezakhani , D. A. Lidar

We study the scattering of two-level atoms at narrow laser fields, modeled by a $\delta$-shape intensity profile. The unique properties of these potentials allow us to give simple analytic solutions for one or two field zones. Several…

Quantum Physics · Physics 2009-11-13 D. Seidel , J. G. Muga , G. C. Hegerfeldt

We experimentally study quantum Zeno effects in a parity-time (PT) symmetric cold atom gas periodically coupled to a reservoir. Based on the state-of-the-art control of inter-site couplings of atoms in a momentum lattice, we implement a…

Quantum Gases · Physics 2021-05-26 Tao Chen , Wei Gou , Dizhou Xie , Teng Xiao , Wei Yi , Jun Jing , Bo Yan

The dynamics of atomic levels resonantly coupled by a coherent and intense short high-frequency laser pulse is discussed and it is advocated that this dynamics is sensitively probed by measuring the spectra of the particles emitted. It is…

Atomic and Molecular Clusters · Physics 2013-01-11 Philipp V. Demekhin , Lorenz S. Cederbaum

We perform stochastic simulations of the quantum Zeno and anti-Zeno effects for two level system and for the decaying one. Instead of simple projection postulate approach, a more realistic model of a detector interacting with the…

Quantum Physics · Physics 2007-05-23 J. Ruseckas , B. Kaulakys

We study the quantum Zeno effect and the anti-Zeno effect in the case of `indirect' measurements, where a measuring apparatus does not act directly on an unstable system, for a realistic model with finite errors in the measurement. A…

Quantum Physics · Physics 2009-11-07 Kazuki Koshino , Akira Shimizu

Exact pointer states are obtained for projection operator measurements performed upon pre-selected (PS) and upon pre- and post-selected (PPS) quantum systems. These states are used to provide simple exact expressions for both the pointer…

Quantum Physics · Physics 2010-10-13 A. D. Parks , J. E. Gray

According to quantum Zeno dynamics (QZD), the evolution of a quantum system can be restricted to a subspace of its Hilbert space by frequent measurements. A crucial question in QZD of a particle's position is: how short the time interval…

Quantum Physics · Physics 2025-10-01 Varqa Abyaneh , Parsa Ghorbani

Frequent Measurements on an unstable particle located at observable initial state freeze the particle on this state, known as quantum Zeno effect [1-14]. Measurements on an observable subspace further open the prelude of quantum Zeno…

Quantum Physics · Physics 2017-02-03 Tung-Ho Shieh , Kun-Yuan Wu , Hsiu-Fen Kao , Kuan-Ming Hung

We study the measurement of the position of atoms as a means to estimate the relative phase between two Bose-Einstein condensates. First, we consider $N$ atoms released from a double-well trap, forming an interference pattern, and show that…

Quantum Gases · Physics 2015-05-20 Jan Chwedenczuk , Francesco Piazza , Augusto Smerzi

The evolution of a quantum system is supposed to be impeded by measurement of an involved observable. This effect has been proven indistinguishable from the effect of dephasing the system's wave function, except in an individual quantum…

Quantum Physics · Physics 2009-11-07 Chr. Balzer , R. Huesmann , W. Neuhauser , P. E. Toschek

Starting from an initial pure quantum state, we present a strategy for reaching a target state corresponding to the extremum (maximum or minimum) of a given observable. We show that a sequence of pulses of moderate intensity, applied at…

Quantum Physics · Physics 2016-08-16 D. Sugny , A. Keller , O. Atabek , D. Daems , C. M. Dion , S. Guérin , H. R. Jauslin