English
Related papers

Related papers: Multiple-copy state discrimination of noisy qubits

200 papers

We theoretically investigate schemes to discriminate between two nonorthogonal quantum states given multiple copies. We consider a number of state discrimination schemes as applied to nonorthogonal, mixed states of a qubit. In particular,…

Quantum Physics · Physics 2015-03-17 B. L. Higgins , A. C. Doherty , S. D. Bartlett , G. J. Pryde , H. M. Wiseman

Quantum state discrimination is a fundamental information processing task that serves as a building block for numerous applications and provides implications at the foundational level. In this work, we consider minimum error discrimination…

Quantum Physics · Physics 2026-04-30 Tim Achenbach , Leevi Leppäjärvi , Hanwool Lee , Teiko Heinosaari

We demonstrate an optical receiver that achieves the quantum Chernoff bound for discriminating coherent states from thermal states in the multi-copy scenario. In contrast, we find that repeated use of the receiver approaching the Helstrom…

Quantum state discrimination is a fundamental primitive in quantum statistics where one has to correctly identify the state of a system that is in one of two possible known states. A programmable discrimination machine performs this task…

Quantum Physics · Physics 2015-05-19 G. Sentís , E. Bagan , J. Calsamiglia , R. Munoz-Tapia

One of the fundamental tenets of quantum mechanics is that non-orthogonal states cannot be distinguished perfectly. When distinguishing multiple copies of a mixed quantum state, a collective measurement, which generates entanglement between…

Quantum Physics · Physics 2025-04-02 Lorcan Conlon , Jin Ming Koh , Biveen Shajilal , Jasminder Sidhu , Ping Koy Lam , Syed M. Assad

In the task of discriminating between nonorthogonal quantum states from multiple copies, the key parameters are the error probability and the resources (number of copies) used. Previous studies have considered the task of minimizing the…

It is a central fact in quantum mechanics that non-orthogonal states cannot be distinguished perfectly. This property ensures the security of quantum key distribution. It is therefore an important task in quantum communication to design and…

Quantum Physics · Physics 2023-11-27 Lorcan O. Conlon , Falk Eilenberger , Ping Koy Lam , Syed M. Assad

We consider the problem of minimum-error quantum state discrimination for single-qubit mixed states. We present a method which uses the Helstrom conditions constructively and analytically; this algebraic approach is complementary to…

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

Discriminating between quantum states is a fundamental problem in quantum information protocols. The optimum approach saturates the Helstrom bound, which quantifies the unavoidable error probability of mistaking one state for another.…

Quantum Physics · Physics 2019-07-24 Shannon Ray , James Schneeloch , Christopher C. Tison , Paul M. Alsing

This work investigates which sets of quantum states give rise to the highest achievable success probability in minimum-error state discrimination if multiple copies of the unknown state are given. Specifically, we consider uniformly…

Ensembles of composite quantum states can exhibit nonlocal behaviour in the sense that their optimal discrimination may require global operations. Such an ensemble containing N pairwise orthogonal pure states, however, can always be…

We present theory and experiment for the task of discriminating two nonorthogonal states, given multiple copies. We implement several local measurement schemes, on both pure states and states mixed by depolarizing noise. We find that…

Quantum Physics · Physics 2009-12-04 B. L. Higgins , B. M. Booth , A. C. Doherty , S. D. Bartlett , H. M. Wiseman , G. J. Pryde

Quantum state discrimination is a fundamental primitive in quantum information processing, underpinning tasks in quantum communication, sensing, and learning. We consider the general Bayes framework, as introduced by Helstrom, for state…

Quantum Physics · Physics 2026-05-01 Ankith Mohan , Jamie Sikora , Sarvagya Upadhyay

The impossibility of perfectly discriminating non orthogonal quantum states imposes far-reaching consequences both on quantum and classical communication schemes. We propose and numerically analyze an optimized quantum receiver for the…

Quantum Physics · Physics 2015-04-02 Christian R. Müller , Christoph Marquardt

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

Unambiguous discrimination and exact cloning reduce the square-overlap between quantum states, exemplifying the more general type of procedure we term state separation. We obtain the maximum probability with which two equiprobable quantum…

Quantum Physics · Physics 2008-11-26 Anthony Chefles , Stephen M. Barnett

We derive a general lower bound on the minimum-error probability for {\it ambiguous discrimination} between arbitrary $m$ mixed quantum states with given prior probabilities. When $m=2$, this bound is precisely the well-known Helstrom…

Quantum Physics · Physics 2009-11-13 Daowen Qiu

The problem of quantum state discrimination between two wave functions of a particle in a square well potential is considered. The optimal minimum-error probability for the state discrimination is known to be given by the Helstrom bound. A…

Quantum Physics · Physics 2010-10-26 Bernhard K. Meister

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

We investigate a scheme of fault-tolerant quantum computation based on the cluster model. Logical qubits are encoded by a suitable code such as the Steane's 7-qubit code. Cluster states of logical qubits are prepared by post-selection…

Quantum Physics · Physics 2007-05-23 Keisuke Fujii , Katsuji Yamamoto
‹ Prev 1 2 3 10 Next ›