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We present an in-depth analysis regarding the error resistance and optimization of our all-optical Bell measurement and ultrafast long-distance quantum communication scheme proposed in [arXiv:1503.06777]. In order to promote our previous…

Quantum Physics · Physics 2017-02-01 Fabian Ewert , Peter van Loock

Bell state analysis (BSA) constitutes a foundational operation for distinguishing Bell states in numerous quantum information processing (QIP) protocols. In this work, we propose a theoretical scheme for realizing a perfect BSA tailored for…

Quantum Physics · Physics 2025-11-24 Zi-Long Yang , Shi-Wen He , Lin-Cheng Wang , Si-Tong Jin , Liu Lv , Xiao-Ming Xiu , Chong Li

Measuring an entangled state of two particles is crucial to many quantum communication protocols. Yet Bell state distinguishability using a finite apparatus obeying linear evolution and local measurement is theoretically limited. We extend…

Quantum Physics · Physics 2011-09-09 N. Pisenti , C. P. E. Gaebler , T. W. Lynn

A complete and deterministic Bell state measurement was realized by a simple linear optics experimental scheme which adopts 2-photon polarization-momentum hyperentanglement. The scheme, which is based on the discrimination among the single…

Quantum Physics · Physics 2008-11-05 M. Barbieri , G. Vallone , P. Mataloni , F. De Martini

Quantum teleportation has proven to be fundamental for many quantum information and communication processes. The core concept can be exploited in many tasks, from the transmission of quantum states, quantum repeaters, to quantum computing.…

Quantum Physics · Physics 2026-01-23 Simone E. D'Aurelio , Matthias J. Bayerbach , Stefanie Barz

We prove limitations on LOCC and separable measurements in bipartite state discrimination problems using techniques from convex optimization. Specific results that we prove include: an exact formula for the optimal probability of correctly…

Bell measurements (BMs) are ubiquitous in quantum information and technology. They are basic elements for quantum commmunication, computation, and error correction. In particular, when performed on logical qubits encoded in physical…

Quantum Physics · Physics 2026-01-14 Simon D. Reiß , Peter van Loock

The use of higher-dimensional photonic encodings (qudits) instead of two-dimensional encodings (qubits) can improve the loss tolerance and reduce the computational resources of photonic-based quantum information processing. To harness this…

Quantum Physics · Physics 2025-04-23 Niv Bharos , Liubov Markovich , Johannes Borregaard

We analyze the linear optical realization of number-sum Bell measurement and number-state manipulation by taking into account the realistic experimental situation, specifically imperfectness of single-photon detector. The present scheme for…

Quantum Physics · Physics 2009-11-10 Akira Kitagawa , Katsuji Yamamoto

Bell's theorem sets a boundary between the classical and quantum realms, by providing a strict proof of the existence of entangled quantum states with no classical counterpart. An experimental violation of Bell's inequality demands…

Despite well-established no-go theorems on a perfect linear optical Bell state analyzer, we find a numerical trend that appears to approach a near-perfect measurement if we incorporate eight or more un-entangled ancilla photons into our…

Quantum Physics · Physics 2018-03-01 Jake A. Smith , Lev Kaplan

We study discrimination of m quantum measurements in the scenario when the unknown measurement with n outcomes can be used only once. We show that ancilla-assisted discrimination procedures provide a nontrivial advantage over simple…

Quantum Physics · Physics 2014-12-01 Michal Sedlak , Mario Ziman

We examine the problem of exhibiting Bell nonlocality for a two-qudit entangled pure state using a randomly chosen set of mutually unbiased bases (MUBs). Interestingly, even if we employ only two-setting Bell inequalities, we find a…

Quantum Physics · Physics 2022-07-19 Gelo Noel M. Tabia , Varun Satya Raj Bavana , Shih-Xian Yang , Yeong-Cherng Liang

We study the problem of closing the detection loophole in three-qubit Bell tests, the experimentally most relevant case beyond the usual bipartite scenario, and show that the minimal detection efficiencies required can be considerably…

Quantum Physics · Physics 2015-08-12 Karoly F. Pal , Tamas Vertesi

A common way to entangle quantum memories is via photonic entanglement swaps. Each of two memories, connected by an optical channel, emits a photonic qubit entangled with itself, and the photonic qubits undergo an entanglement swap on a…

Quantum Physics · Physics 2023-09-20 Prajit Dhara , Dirk Englund , Saikat Guha

We theoretically investigate the distinguishability of a set of mutually orthogonal four-dimensional Bell states of photon system in path degree of freedom using only linear optics, resorting to the two-photon interference. With quantum…

Quantum Physics · Physics 2025-01-23 Zhi Zeng

The problem of unambiguous state discrimination consists of determining which of a set of known quantum states a particular system is in. One is allowed to fail, but not to make a mistake. The optimal procedure is the one with the lowest…

Quantum Physics · Physics 2009-11-07 Mark Hillery , Jihane Mimih

We show that the detection efficiencies required for closing the detection loophole in Bell tests can be significantly lowered using quantum systems of dimension larger than two. We introduce a series of asymmetric Bell tests for which an…

Quantum Physics · Physics 2010-02-22 Tamas Vertesi , Stefano Pironio , Nicolas Brunner

We propose a projection measurement onto encoded Bell states with a static network of linear optical elements. By increasing the size of the quantum error correction code, both Bell measurement efficiency and photon-loss tolerance can be…

Quantum Physics · Physics 2016-11-23 Fabian Ewert , Marcel Bergmann , Peter van Loock

Photon counting induces an effective nonlinear optical phase shift on certain states derived by linear optics from single photons. Although this no nlinearity is nondeterministic, it is sufficient in principle to allow scalable linear…

Quantum Physics · Physics 2007-05-23 T. C. Ralph , A. P. Lund , H. M. Wiseman