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Related papers: Photonic quantum metrology with variational quantu…

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Programmable photonic quantum processors face a critical challenge: despite significant advances in quantum state preparation and manipulation, measurements remain limited to projective techniques. Here, we demonstrate a programmable…

The polarizing multi-photon quantum states tomography with non-unit quantum efficiency of detectors is considered. A new quantum tomography protocol is proposed. This protocol considers events of losing photons of multi-photon quantum state…

Quantum Physics · Physics 2018-02-14 Yu. I. Bogdanov , B. I. Bantysh , N. A. Bogdanova , V. F. Lukichev

Two-photon absorption (TPA) is of fundamental importance in super-resolution imaging and spectroscopy. Its nonlinear character allows for the prospect of using quantum resources, such as entanglement, to improve measurement precision or to…

Quantum Physics · Physics 2021-09-22 Carlos Sánchez Muñoz , Gaetano Frascella , Frank Schlawin

Estimation of quantum states and measurements is crucial for the implementation of quantum information protocols. The standard method for each is quantum tomography. However, quantum tomography suffers from systematic errors caused by…

Quantum Physics · Physics 2018-10-19 Adam C. Keith , Charles H. Baldwin , Scott Glancy , E. Knill

As information carriers in quantum computing, photonic qubits have the advantage of undergoing negligible decoherence. However, the absence of any significant photon-photon interaction is problematic for the realization of non-trivial…

Quantum fluctuations are fundamental in quantum technologies, affecting computing, sensing, cryptography, and thermodynamics. These include fluctuations in the variation of energy, charge, and other observables driven by interactions with…

Quantum Physics · Physics 2025-09-18 Thales Augusto Barbosa Pinto Silva , David Gelbwaser-Klimovsky

Quantum metrology enables estimation of optical phase shifts with precision beyond the shot-noise limit. One way to exceed this limit is to use squeezed states, where the quantum noise of one observable is reduced at the expense of…

Multi-photon quantum interference is the underlying principle for optical quantum information processing protocols. Indistinguishability is the key to quantum interference. Therefore, the success of many protocols in optical quantum…

Quantum Physics · Physics 2020-09-23 Liang Cui , Jie Su , Jiamin Li , Yuhong Liu , Xiaoying Li , Z. Y. Ou

Precision metrology and quantum measurement often demand matter be prepared in well defined quantum states for both internal and external degrees of freedom. Laser-cooled neutral atoms localized in a deeply confining optical potential…

Quantum Physics · Physics 2009-11-13 Jun Ye , H. J. Kimble , Hidetoshi Katori

Quantum effects in metrology can in principle enhance measurement precision from the so-called standard quantum limit to the Heisenberg Limit. Further advancements in quantum metrology largely rely on innovative metrology protocols that can…

Quantum Physics · Physics 2025-06-16 Zhixing Zou , Jiangbin Gong , Weitao Chen

Quantum metrology uses quantum states with no classical counterpart to measure a physical quantity with extraordinary sensitivity or precision. Most metrology schemes measure a single parameter of a dynamical process by probing it with a…

Quantum Physics · Physics 2014-11-11 Lee A. Rozema , Dylan H. Mahler , Robin Blume-Kohout , Aephraim M. Steinberg

Critical phenomena of quantum systems offer a promising strategy to improve measurement precision. So far, many criticality-enhanced quantum metrological schemes have been proposed by using the adiabatically evolved photonic states of…

Quantum Physics · Physics 2026-03-31 Ken Chen , Jia-Hao Lv , Wen Ning , Zhen-Biao Yang , Shi-Biao Zheng

A major roadblock for large-scale photonic quantum technologies is the lack of practical reliable certification tools. We introduce an experimentally friendly - yet mathematically rigorous - certification test for experimental preparations…

Quantum Physics · Physics 2015-12-03 L. Aolita , C. Gogolin , M. Kliesch , J. Eisert

The sensitivity of classical and quantum sensing is impaired in a noisy environment. Thus, one of the main challenges facing sensing protocols is to reduce the noise while preserving the signal. State of the art quantum sensing protocols…

Optics · Physics 2016-07-18 L. Cohen , Y. Pilnyak , D. Istrati , A. Retzker , H. S. Eisenberg

Precision metrology underpins scientific and technological advancements. Quantum metrology offers a pathway to surpass classical sensing limits by leveraging quantum states and measurement strategies. However, measuring multiple…

Quantum metrology bears a great promise in enhancing measurement precision, but is unlikely to become practical in the near future. Its concepts can nevertheless inspire classical or hybrid methods of immediate value. Here, we demonstrate…

To acquire the best path-entangled photon Fock states for robust quantum optical metrology with parity detection, we calculate phase information from a lossy interferometer by using twin entangled Fock states. We show that (a) when loss is…

Quantum Physics · Physics 2013-05-30 Kebei Jiang , Chase J. Brignac , Yi Weng , Moochan B. Kim , Hwang Lee , Jonathan P. Dowling

Quantum technologies promise profound advances in communication security, sensing and computing. The underpinning hardware must be engineered to generate, manipulate and detect quantum phenomena with exceptional performance, whilst being…

Quantum Physics · Physics 2025-07-15 R. N. Clark , B. Puzio , O. M. Green , S. T. Pradyumna , O. Trojak , A. Politi , J. C. F. Matthews

Quantum metrology overcomes standard precision limits by exploiting collective quantum superpositions of physical systems used for sensing, with the prominent example of non-classical multiphoton states improving interferometric techniques.…

The scalable preparation of bosonic quantum states with macroscopic excitations poses a fundamental challenge in quantum technologies, limited by control complexity and photon-loss rates that severely constrain prior theoretical and…