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The asymptotic state discrimination problem with simple hypotheses is considered for a cubic lattice of bosons. A complete solution is provided for the problems of the Chernoff and the Hoeffding bounds and Stein's lemma in the case when…

Quantum Physics · Physics 2009-11-13 Milan Mosonyi

Robust, accurate and efficient quantum tomography is key for future quantum technologies. Traditional methods are impractical for even medium sized systems and are not robust against noise and errors. Here we report on an experimental…

Quantum Physics · Physics 2016-07-27 Robert J. Chapman , Christopher Ferrie , Alberto Peruzzo

The measurement based, or one-way, model of quantum computation for continuous variables uses a highly entangled state called a cluster state to accomplish the task of computing. Cluster states that are universal for computation are a…

Quantum Physics · Physics 2019-12-11 Darren W. Moore

BosonSampling is a quantum mechanical task involving Fock basis state preparation and detection and evolution using only linear interactions. A classical algorithm for producing samples from this quantum task cannot be efficient unless the…

Quantum Physics · Physics 2017-08-09 A. P. Lund , S. Rahimi-Keshari , T. C. Ralph

Gaussian boson sampling is a promising scheme for demonstrating a quantum computational advantage using photonic states that are accessible in a laboratory and, thus, offer scalable sources of quantum light. In this contribution, we study…

Quantum Physics · Physics 2019-02-22 D. S. Phillips , M. Walschaers , J. J. Renema , I. A. Walmsley , N. Treps , J. Sperling

We determine the optimal method of discriminating and comparing quantum states from a certain class of multimode Gaussian states and their mixtures when arbitrary global Gaussian operations and general Gaussian measurements are allowed. We…

Measures of entanglement, fidelity and purity are basic yardsticks in quantum information processing. We propose how to implement these measures using linear devices and homodyne detectors for continuous variable Gaussian states. In…

Quantum Physics · Physics 2009-11-07 M. S. Kim , Jinhyoung Lee , W. J. Munro

Cubic phase states provide the essential non-Gaussian resource for continuous-variable quantum computing. We show that they also offer significant potential for quantum metrology, surpassing the phase-sensing sensitivity of all Gaussian…

Quantum Physics · Physics 2025-12-04 Jiajie Guo , Shuheng Liu , Boxuan Jing , Qiongyi He , Manuel Gessner

Continuous-variable quantum information, encoded into infinite-dimensional quantum systems, is a promising platform for the realization of many quantum information protocols, including quantum computation, quantum metrology, quantum…

Quantum Physics · Physics 2021-06-17 Ya-Dong Wu , Ge Bai , Giulio Chiribella , Nana Liu

We present a novel, non-parametric form for compactly representing entangled many-body quantum states, which we call a `Gaussian Process State'. In contrast to other approaches, we define this state explicitly in terms of a configurational…

Strongly Correlated Electrons · Physics 2020-11-11 Aldo Glielmo , Yannic Rath , Gabor Csanyi , Alessandro De Vita , George H. Booth

Gaussian quantum states hold special importance in the continuous variable (CV) regime. In quantum information science, the understanding and characterization of central resources such as entanglement may strongly rely on the knowledge of…

Quantum Physics · Physics 2015-07-21 A. S. Coelho , F. A. S. Barbosa , K. N. Cassemiro , M. Martinelli , A. S. Villar , P. Nussenzveig

Gaussian boson sampling exploits squeezed states to provide a highly efficient way to demonstrate quantum computational advantage. We perform experiments with 50 input single-mode squeezed states with high indistinguishability and squeezing…

Continuous-variable (CV) cluster states are a universal resource for fault-tolerant quantum computation when supplemented with the Gottesman-Kitaev-Preskill (GKP) bosonic code. We generalize the recently introduced subsystem decomposition…

Quantum Physics · Physics 2021-08-09 Giacomo Pantaleoni , Ben Q. Baragiola , Nicolas C. Menicucci

We consider Gaussian quantum circuits supplemented with non-Gaussian input states and derive sufficient conditions for efficient classical strong simulation of these circuits. In particular, we generalise the stellar representation of…

Quantum Physics · Physics 2021-07-14 Ulysse Chabaud , Giulia Ferrini , Frédéric Grosshans , Damian Markham

We extend the quantum discord to continuous variable systems and evaluate Gaussian quantum discord C(\rho) for bipartite Gaussian states. In particular, for squeezed thermal states (STS), we explicitly maximize the extractable information…

Quantum Physics · Physics 2015-05-18 Paolo Giorda , Matteo G. A. Paris

Continuous-variable quantum systems are foundational to quantum computation, communication, and sensing. While traditional representations using wave functions or density matrices are often impractical, the tomographic picture of quantum…

Quantum Physics · Physics 2026-03-17 Liubov A. Markovich , Xiaoyu Liu , Jordi Tura

We provide a unified graphical calculus for all Gaussian pure states, including graph transformation rules for all local and semi-local Gaussian unitary operations, as well as local quadrature measurements. We then use this graphical…

Quantum Physics · Physics 2011-04-29 Nicolas C. Menicucci , Steven T. Flammia , Peter van Loock

While negativity in phase space is a well-known signature of nonclassicality, a wide variety of nonclassical states require their characterization beyond negativity. We establish a framework of nonclassicality in phase space that addresses…

Quantum Physics · Physics 2021-12-30 Jiyong Park , Jaehak Lee , Hyunchul Nha

Quantum non-Gaussianity is a key resource for quantum advantage in continuous-variable systems. We introduce a general framework to quantify non-Gaussianity based on correlation generation: two copies of a state become correlated at a…

Quantum Physics · Physics 2025-08-28 Oliver Hahn , Ryuji Takagi

Quantum state tomography is the task of inferring the state of a quantum system by appropriate measurements. Since the frequency distributions of the outcomes of any finite number of measurements will generally deviate from their asymptotic…

Quantum Physics · Physics 2012-11-08 Matthias Christandl , Renato Renner