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Related papers: Maximal randomness from partially entangled states

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Quantum random number generator harnesses the power of quantum mechanics to generate true random numbers, making it valuable for various scientific applications. However, real-world devices often suffer from imperfections that can undermine…

Quantum Physics · Physics 2023-12-07 Xing Lin , Rong Wang

We demonstrate one-sided device-independent self-testing of any pure entangled two-qubit state based on a fine-grained steering inequality. The maximum violation of a fine-grained steering inequality can be used to witness certain steerable…

Quantum Physics · Physics 2020-05-06 Zhihao Bian , A. S. Majumdar , C. Jebaratnam , Kunkun Wang , Lei Xiao , Xiang Zhan , Yongsheng Zhang , Peng Xue

We undertake experimental detection of the entanglement present in arbitrary three-qubit pure quantum states on an NMR quantum information processor. Measurements of only four observables suffice to experimentally differentiate between the…

Quantum Physics · Physics 2018-09-06 Amandeep Singh , Harpreet Singh , Kavita Dorai , Arvind

Quantum properties of the probes used to estimate a classical parameter can be used to attain accuracies that beat the standard quantum limit. When qubits are used to construct a quantum probe, it is known that initializing $n$ qubits in an…

Quantum Physics · Physics 2009-11-13 Anil Shaji , Carlton M. Caves

We analyze various scenarios for entangling two initially unentangled qubits. In particular, we propose an optimal universal entangler which entangles a qubit in unknown state $|\Psi>$ with a qubit in a reference (known) state $|0>$. That…

Quantum Physics · Physics 2009-11-06 Vladimir Buzek , Mark Hillery

The generation of random numbers via quantum processes is an efficient and reliable method to obtain true indeterministic random numbers that are of vital importance to cryptographic communication and large-scale computer modeling. However,…

Quantum Physics · Physics 2015-05-20 J. Y. Haw , S. M. Assad , A. M. Lance , N. H. Y. Ng , V. Sharma , P. K. Lam , T. Symul

We use Nuclear Magnetic Resonance (NMR) to experimentally generate a bound entangled (more precisely: pseudo bound entangled) state, i.e. a quantum state which is non-distillable but nevertheless entangled. Our quantum system consists of…

Quantum Physics · Physics 2010-11-08 H. Kampermann , X. Peng , D. Bruss , D. Suter

Within the quantum networks scenario we introduce a single scheme allowing to certify three different types of composite projective measurements acting on a three-qubit Hilbert space: one constructed from genuinely entangled GHZ-like…

Quantum Physics · Physics 2025-05-20 Shubhayan Sarkar , Chandan Datta , Saronath Halder , Remigiusz Augusiak

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 describe a methodology and standard of proof for experimental claims of quantum random number generation (QRNG), analogous to well-established methods from precision measurement. For appropriately constructed physical implementations,…

Quantum Physics · Physics 2015-01-14 Morgan W. Mitchell , Carlos Abellan , Waldimar Amaya

We present an end-to-end and practical randomness amplification and privatisation protocol based on Bell tests. This allows the building of device-independent random number generators which output (near-)perfectly unbiased and private…

Quantum Physics · Physics 2023-04-05 Cameron Foreman , Sherilyn Wright , Alec Edgington , Mario Berta , Florian J. Curchod

We experimentally demonstrate the superior discrimination of separated, unentangled two-qubit correlated states using nonlocal measurements, when compared with measurements based on local operations and classical communications. When…

Quantum Physics · Physics 2008-11-26 G. J. Pryde , J. L. O'Brien , A. G. White , Stephen D. Bartlett

The generation of series of random numbers is an important and difficult problem. Even the very definition of random is difficult. Appropriate measurements on entangled states have been proposed as the definitive solution to produce series…

Quantum Physics · Physics 2023-04-26 Myriam Nonaka , Mónica Agüero , Marcelo Kovalsky , Alejandro Hnilo

We discuss what can be inferred from measurements on one- and two-qubit systems using a single measurement basis at various times. We show that, given reasonable physical assumptions, carrying out such measurements at quarter-period…

Quantum Physics · Physics 2010-08-23 Bella Schelpe , Adrian Kent , William Munro , Tim Spiller

Self-testing refers to a method with which a classical user can certify the state and measurements of quantum systems in a device-independent way. Especially, the self-testing of entangled states is of great importance in quantum…

Entanglement is one of the key resources required for quantum computation, so experimentally creating and measuring entangled states is of crucial importance in the various physical implementations of a quantum computer. In superconducting…

Quantum random number generators (QRNGs) harness the intrinsic randomness in measurement processes: the measurement outputs are truly random given the input state is a superposition of the eigenstates of the measurement operators. In the…

Quantum Physics · Physics 2017-11-29 Bing Qi

We assess the quality of a source of allegedly pure two-qubit states using both standard tomography and methods inspired by device-independent self-testing. Even when the detection and locality loopholes are open, the latter methods can…

Quantum Physics · Physics 2019-08-08 Koon Tong Goh , Chithrabhanu Perumangatt , Zhi Xian Lee , Alexander Ling , Valerio Scarani

It is now experimentally possible to entangle thousands of qubits, and efficiently measure each qubit in parallel in a distinct basis. To fully characterize an unknown entangled state of $n$ qubits, one requires an exponential number of…

Quantum Physics · Physics 2020-03-18 Jordan Cotler , Frank Wilczek

Non-projective measurements play a crucial role in various information-processing protocols. In this work, we propose an operational task to identify measurements that are neither projective nor classical post-processing of data obtained…

Quantum Physics · Physics 2025-04-01 Sumit Rout , Some Sankar Bhattacharya , Paweł Horodecki