English
Related papers

Related papers: Dynamical Quantum Tomography

200 papers

We present a method for measuring quantum states encoded in the temporal modes of photons. The basis for the multilevel quantum states is defined by the use of modes propagating in a dispersive medium, which is a fiber in this case. The…

Quantum Physics · Physics 2020-11-26 Karolina Sedziak-Kacprowicz , Artur Czerwinski , Piotr Kolenderski

The measurement of quantum states is one of the most important problems in quantum mechanics. We introduce a quantum state tomography technique in which the state of a qubit is reconstructed, while the qubit remains undetected. The key…

We describe an algorithm for quantum state tomography that converges in polynomial time to an estimate, together with a rigorous error bound on the fidelity between the estimate and the true state. The result suggests that state tomography…

Quantum Physics · Physics 2010-02-23 Steven T. Flammia , David Gross , Stephen D. Bartlett , Rolando Somma

Suppose you receive a sequence of qubits where each qubit is guaranteed to be in one of two pure states, but you do not know what those states are. Your task is to determine the states. This can be viewed as a kind of quantum state learning…

Quantum state tomography (QST) aims at estimating a quantum state from averaged quantum measurements made on copies of the state. Most quantum algorithms rely on QST at some point and it is a well explored topic in the literature, mostly…

Quantum Physics · Physics 2023-01-18 François Verdeil , Yannick Deville

A single photon has many physical degrees of freedom (DOF) that can carry the state of a high-dimensional quantum system. Nevertheless, only a single DOF is usually used in any specific demonstration. Furthermore, when more DOF are being…

Quantum Physics · Physics 2019-10-23 Yehuda Pilnyak , Pini Zilber , Lior Cohen , Hagai S. Eisenberg

We explore the possibility of using "weak" measurements to carry out quantum state tomography. Given a certain fixed number of copies of identically prepared states of a qubit, we simulate state tomography using weak as well as projective…

Quantum Physics · Physics 2014-08-06 Debmalya Das , Arvind

We consider the problem of determining the mixed quantum state of a large but finite number of identically prepared quantum systems from data obtained in a sequence of ideal (von Neumann) measurements, each performed on an individual copy…

Quantum Physics · Physics 2009-11-10 Franz Embacher , Heide Narnhofer

State discrimination is a useful test problem with which to clarify the power and limitations of different classes of measurement. We consider the problem of discriminating between given states of a bi-partite quantum system via sequential…

Quantum Physics · Physics 2017-09-25 Sarah Croke , Stephen M. Barnett , Graeme Weir

Quantum tomography is a critically important tool to evaluate quantum hardware, making it essential to develop optimized measurement strategies that are both accurate and efficient. We compare a variety of strategies using nearly pure test…

Quantum Physics · Physics 2017-10-18 H. Sosa-Martinez , N. K. Lysne , C. H. Baldwin , A. Kalev , I. H. Deutsch , P. S. Jessen

The possibility of determining the state of a quantum system after a continuous measurement of position is discussed in the framework of quantum trajectory theory. Initial lack of knowledge of the system and external noises are accounted…

Quantum Physics · Physics 2009-10-31 A. C. Doherty , S. M. Tan , A. S. Parkins , D. F. Walls

In this article we propose a dynamic quantum tomography model for open quantum systems with evolution given by phase-damping channels. Mathematically, these channels correspond to completely positive trace-preserving maps defined by the…

Quantum Physics · Physics 2020-01-07 Artur Czerwinski , Andrzej Jamiolkowski

Quantum states can be described equivalently by density matrices, Wigner functions or quantum tomograms. We analyze the accuracy and performance of three related semiclassical approaches to quantum dynamics, in particular with respect to…

Quantum Physics · Physics 2009-08-27 G. Schubert , V. S. Filinov , K. Matyash , R. Schneider , H. Fehske

We propose and analyze quantum state estimation (tomography) using continuous quantum measurements with resource limitations, allowing the global state of many qubits to be constructed from only measuring a few. We give a proof-of-principle…

Quantum Physics · Physics 2020-04-13 Areeya Chantasri , Shengshi Pang , Teerawat Chalermpusitarak , Andrew N. Jordan

We present a new procedure for quantum state reconstruction based on weak continuous measurement of an ensemble average. By applying controlled evolution to the initial state new information is continually mapped onto the measured…

Quantum Physics · Physics 2009-11-10 Andrew Silberfarb , Poul S. Jessen , Ivan H. Deutsch

We present a formalism for self-calibrating tomography of arbitrary dimensional systems. Self-calibrating quantum state tomography was first introduced in the context of qubits, and allows the reconstruction of the density matrix of an…

Quantum Physics · Physics 2013-06-26 Nicolás Quesada , Agata M. Brańczyk , Daniel F. V. James

Quantum measurement is essential to both the foundations and practical applications of quantum information science. Among many possible models of quantum measurement, feedback measurements that dynamically update their physical structure…

Quantum Physics · Physics 2020-02-25 Shuro Izumi , Jonas S. Neergaard-Nielsen , Ulrik L. Andersen

We study quantum tomography based on a stochastic continuous-time measurement record obtained from a probe field collectively interacting with an ensemble of identically prepared systems. In comparison to previous studies, we consider here…

Quantum Physics · Physics 2014-10-01 Robert L. Cook , Carlos A. Riofrío , Ivan H. Deutsch

There are fundamental limits to the accuracy with which one can determine the state of a quantum system. I give an overview of the main approaches to quantum state discrimination. Several strategies exist. In quantum hypothesis testing, a…

Quantum Physics · Physics 2009-11-06 Anthony Chefles

Characterization of quantum processes is a preliminary step necessary in the development of quantum technology. The conventional method uses standard quantum process tomography, which requires $d^2$ input states and $d^4$ quantum…

Quantum Physics · Physics 2020-02-26 Zhibo Hou , Jun-Feng Tang , Christopher Ferrie , Guo-Yong Xiang , Chuan-Feng Li , Guang-Can Guo
‹ Prev 1 3 4 5 6 7 10 Next ›