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We introduce novel schemes for quantum computing based on local measurements on entangled resource states. This work elaborates on the framework established in [Phys. Rev. Lett. 98, 220503 (2007), quant-ph/0609149]. Our method makes use of…

Quantum Physics · Physics 2009-11-13 D. Gross , J. Eisert , N. Schuch , D. Perez-Garcia

The classical simulation of quantum systems typically requires exponential resources. Recently, the introduction of a machine learning-based wavefunction ansatz has led to the ability to solve the quantum many-body problem in regimes that…

Disordered Systems and Neural Networks · Physics 2019-10-24 Joseph Gomes , Keri A. McKiernan , Peter Eastman , Vijay S. Pande

So far, only the results on 3 qubit spaces (both on superconducting and ion-trap realisations of quantum processors) have beaten the classical unstructured search in the expected number of oracle calls using optimal protocols in both…

It is well known that quantum computers can efficiently find a hidden subgroup $H$ of a finite Abelian group $G$. This implies that after only a polynomial (in $\log |G|$) number of calls to the oracle function, the states corresponding to…

Quantum Physics · Physics 2007-05-23 Mark Ettinger , Peter Hoyer , Emanuel Knill

Since Grover's seminal work which provides a way to speed up combinatorial search, quantum search has been studied in great detail. We propose a new method for designing quantum search algorithms for finding a marked element in the state…

Quantum Physics · Physics 2012-08-07 R. Sufiani , N. Bahari

In the realm of quantum information processing, the efficient characterization of entangled states poses an overwhelming challenge, rendering the traditional methods including quantum tomography unfeasible and impractical. To tackle this…

Quantum Physics · Physics 2025-12-09 Ye-Chao Liu , Jiangwei Shang

Entangled quantum systems have properties that have fundamentally overthrown the classical worldview. Increasing the complexity of entangled states by expanding their dimensionality allows the implementation of novel fundamental tests of…

Quantum Physics · Physics 2014-05-01 Mario Krenn , Marcus Huber , Robert Fickler , Radek Lapkiewicz , Sven Ramelow , Anton Zeilinger

Unstructured search remains as one of the significant challenges in computer science, as classical search algorithms become increasingly impractical for large-scale systems due to their linear time complexity. Quantum algorithms, notably…

Quantum Physics · Physics 2025-05-22 Harishankar Mishra , Asvija Balasubramanyam , Gudapati Naresh Raghava

Grover discovered a quantum algorithm for identifying a target element in an unstructured search universe of N items in approximately square-root of N queries to a quantum oracle, thus achieving a square-root speed-up over classical…

Quantum Physics · Physics 2007-05-23 Erdal Arikan

Studying the behavior of quantum information scrambling in various quantum systems is an active area of research. Recently, Sharma et al. [K.K. Sharma, V.P Gerdt, Quantum Inf. Process 20, 195 (2021)] have shown the mathematical connection…

Quantum Physics · Physics 2024-08-27 Kapil K. Sharma , Rishikant Rajdeepak , Ashok Kumar , Prasanta K. Panigrahi

Understanding the role that quantum entanglement plays as a resource in various information processing tasks is one of the crucial goals of quantum information theory. Here we propose a new perspective for studying quantum entanglement:…

Quantum Physics · Physics 2015-09-23 L. Czekaj , M. Pawlowski , T. Vertesi , A. Grudka , M. Horodecki , R. Horodecki

Coherent states with large amplitudes are traditionally thought of as the best quantum mechanical approximation of classical behavior. Here we argue that, far from being classical, coherent state are in fact highly entangled. We demonstrate…

Quantum Physics · Physics 2007-05-23 D. Kaszlikowski , V. Vedral

A quantum analog of the fundamental classical NOT gate is a quantum gate that would transform any input qubit state onto an orthogonal state. Intriguingly, this universal NOT gate is forbidden by the laws of quantum physics. This striking…

Quantum Physics · Physics 2015-06-19 M. Jezek , M. Micuda , I. Straka , M. Mikova , M. Dusek , J. Fiurasek

This work studies the variational quantum eigensolver algorithm, designed to determine the ground state of a quantum mechanical system by combining classical and quantum hardware. Methods of reducing the number of required qubit…

Quantum Physics · Physics 2022-03-01 R. J. P. T. de Keijzer , V. E. Colussi , B. Škorić , S. J. J. M. F. Kokkelmans

Description of nonclassicality of states has hitherto been through violation of Bell inequality and non-separability, with the latter being a stronger constraint. In this paper, we show that this can be further sharpened, by introducing the…

Quantum Physics · Physics 2015-06-18 H. M. Bharath , V. Ravishankar

We introduce an algorithm for combinatorial search on quantum computers that is capable of significantly concentrating amplitude into solutions for some NP search problems, on average. This is done by exploiting the same aspects of problem…

Quantum Physics · Physics 2007-05-23 Tad Hogg

We introduce an algorithm for combinatorial search on quantum computers that is capable of significantly concentrating amplitude into solutions for some NP search problems, on average. This is done by exploiting the same aspects of problem…

Artificial Intelligence · Computer Science 2009-09-25 T. Hogg

We provide a quantum gambling protocol using three (symmetric) nonorthogonal states. The bias of the proposed protocol is less than that of previous ones, making it more practical. We show that the proposed scheme is secure against…

Quantum Physics · Physics 2009-11-07 W. -Y. Hwang , K. Matsumoto

Quantum search is a quantum mechanical technique for searching N possibilities in only sqrt(N) steps. This has been proved to be the best possible algorithm for the exhuastive search problem in the sense the number of queries it requires…

Quantum Physics · Physics 2009-11-07 Lov K. Grover

We study a quantum analogue of locally decodable error-correcting codes. A q-query locally decodable quantum code encodes n classical bits in an m-qubit state, in such a way that each of the encoded bits can be recovered with high…

Quantum Physics · Physics 2008-06-13 Jop Briët , Ronald de Wolf