English
Related papers

Related papers: Direct measurement of the two-point function in qu…

200 papers

Quantum optics plays a central role in the study of fundamental concepts in quantum mechanics, and in the development of new technological applications. Typical experiments employ non-classical light, such as entangled photons, generated by…

We present a time-dependent quantum calculations of the first order and second order photon correlation functions for the scattering of a single-photon pulse on a two-level atom (qubit) embedded in a one-dimensional open waveguide. Within…

Quantum Physics · Physics 2025-11-05 Ya. S. Greenberg. O. A. Chuikin , A. G. Moiseev , A. A. Shtygashev

Recent work [J.S. Lundeen et al. Nature, 474, 188 (2011)] directly measured the wavefunction by weakly measuring a variable followed by a normal (i.e. `strong') measurement of the complementary variable. We generalize this method to mixed…

Quantum Physics · Physics 2012-03-14 Jeff S. Lundeen , Charles Bamber

The measurement process is considered for quantum field theory on curved spacetimes. Measurements are carried out on one QFT, the "system", using another, the "probe" via a dynamical coupling of "system" and "probe" in a bounded spacetime…

Mathematical Physics · Physics 2020-07-27 Christopher J. Fewster , Rainer Verch

We measure many-body interactions in isolated quantum dot states using double-quantum multidimensional coherent spectroscopy. Few states are probed in a diffraction limited spot, which is enabled by a novel collinear scheme in which…

Mesoscale and Nanoscale Physics · Physics 2018-02-21 Eric W. Martin , Steven T. Cundiff

We provide a measurement protocol to estimate 2- and 4-point fermionic correlations in ultra-cold atom experiments. Our approach is based on combining random atomic beam splitter operations, which can be realized with programmable optical…

We study the two-photon scattering processes in a one-dimensional waveguide coupled to a two- or three-level giant atom, respectively. The accumulated phase shift between the two coupling points can be utilized to alter the scattering…

Quantum Physics · Physics 2023-11-30 Wenju Gu , He Huang , Zhen Yi , Lei Chen , Lihui Sun , Huatang Tan

In this report, we study the reduced conditional dynamics of a quantum system in the case of indirect quantum measurement. The detectors microscopic part (pointer) interacts with the measured system (target) and the environment, which…

Quantum Physics · Physics 2013-11-06 George Miroshnichenko , Alexander Trifanov

We consider a continuous measurement of a two-level system (double-dot) by weakly coupled detector (tunnel point contact nearby). While usual treatment leads to the gradual system decoherence due to the measurement, we show that the…

Quantum Physics · Physics 2007-05-23 Alexander N. Korotkov

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

Entanglement plays a fundamental role in quantum physics and information processing. Here, we develop an unbiased estimator for mixed-state entanglement in the few-shot scenario and directly estimate it using random unitary evolution in a…

Quantum Physics · Physics 2024-07-09 Gong-Chu Li , Lei Chen , Si-Qi Zhang , Xu-Song Hong , You Zhou , Geng Chen , Chuan-Feng Li , Guang-Can Guo

A definition of quantum correlation is presented for an arbitrary bipartite quantum state based on the skew information. This definition not only inherits the good properties of skew information such as the contractivity and so on, but also…

Quantum Physics · Physics 2015-06-17 Chang-shui Yu , Shao-xiong Wu , Xiao-guang Wang , X. X. Yi , He-shan Song

While commonly used entanglement criteria for continuous variable systems are based on quadrature measurements, here we study entanglement detection from measurements of the Wigner function. These are routinely performed in platforms such…

Quantum Physics · Physics 2026-03-25 Shuheng Liu , Jiajie Guo , Qiongyi He , Matteo Fadel

We discuss the conditional measurement of field amplitudes by a nonclassical photon sequence in the Jaynes-Cummings (JC) model under multiphoton operation. We do so by employing a correlator of immediate experimental relevance to reveal a…

Quantum Physics · Physics 2024-03-14 Th. K. Mavrogordatos

Experiments on trapped quantum gases can probe challenging regimes of quantum many-body dynamics, where strong interactions or non-equilibrium states prevent exact solutions. Here we present an exact result which holds even when no exact…

Quantum Gases · Physics 2016-10-19 Etienne Wamba , Axel Pelster , James R. Anglin

We report the experimental measurement of bipartite quantum correlations of an unknown two-qubit state. Using a liquid state Nuclear Magnetic Resonance (NMR) setup and employing geometric discord, we evaluate the quantum correlations of a…

In this letter, we have considered an electron in a double quantum dot system interacting with a detector represented by a point contact. We present a dynamical model for the gradual decoherence of the density matrix due to the interaction…

Mesoscale and Nanoscale Physics · Physics 2017-11-29 H. Cruz

We present a quantum circuit that implements a non-demolition measurement of complementary single- and bi-partite properties of a two-qubit system: entanglement and single-partite visibility and predictability. The system must be in a pure…

Quantum Physics · Physics 2007-06-20 F. de Melo , S. P. Walborn , János A. Bergou , L. Davidovich

In this note, we study two-point correlation functions of modular Hamiltonians. We show that in general quantum systems, these correlators obey properties similar to those of von Neumann entropy and capacity of entanglement, both of which…

High Energy Physics - Theory · Physics 2025-06-13 Mathew W. Bub , Allic Sivaramakrishnan

Here, we point out that interactions with time delay can be described at the quantum level using a multi-time wave function $\psi(x_1,...,x_N)$, i.e., a wave function depending on one spacetime variable $x_i = (t_i,\mathbf{x}_i)$ per…

Quantum Physics · Physics 2018-10-09 Matthias Lienert