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We develop a geometric approach to quantify the capability of creating entanglement for a general physical interaction acting on two qubits. We use the entanglement measure proposed by us for $N$-qubit pure states (PRA \textbf{77}, 062334…

Quantum Physics · Physics 2015-05-13 Behzad Lari , Ali Saif M. Hassan , Pramod S. Joag

Our current understanding of quantum chaos in many-body quantum systems hinges on the random matrix theory(RMT) behavior of eigenstates and their energy level statistics. Although RMT has been remarkably successful in describing `coarse'…

Statistical Mechanics · Physics 2025-08-05 Christopher M. Langlett , Joaquin F. Rodriguez-Nieva

Hypergraph states are multiqubit states whose combinatorial description and entanglement properties generalize the well-studied class of graph states. Graph states are important in applications such as measurement-based quantum computation…

Quantum Physics · Physics 2015-02-06 David W. Lyons , Daniel J. Upchurch , Scott N. Walck , Chase D. Yetter

The recently-defined No Low-energy Sampleable States (NLSS) conjecture of Gharibian and Le Gall [GL22] posits the existence of a family of local Hamiltonians where all states of low-enough constant energy do not have succinct…

Quantum Physics · Physics 2023-07-21 Nolan J. Coble , Matthew Coudron , Jon Nelson , Seyed Sajjad Nezhadi

It is well known that an exponentially localized Hamiltonian must be gapless if its ground state has algebraic correlations. We show that even certain exponentially decaying correlations can imply gaplessness. This is exemplified by the…

Strongly Correlated Electrons · Physics 2025-04-29 Rahul Sahay , Curt von Keyserlingk , Ruben Verresen , Carolyn Zhang

The Markov property entails the conditional independence structure inherent in Gibbs distributions for general classical Hamiltonians, a feature that plays a crucial role in inference, mixing time analysis, and algorithm design. However,…

Quantum Physics · Physics 2025-04-04 Chi-Fang Chen , Cambyse Rouzé

The space of quantum Hamiltonians has a natural partition in classes of operators that can be adiabatically deformed into each other. We consider parametric families of Hamiltonians acting on a bi-partite quantum state-space. When the…

Quantum Physics · Physics 2009-11-10 Alioscia Hamma , Paolo Zanardi

We consider a one-dimensional spin chain for which the ground state is the cluster state, capable of functioning as a quantum computational wire when subjected to local adaptive measurements of individual qubits, and investigate the…

Quantum Physics · Physics 2009-08-13 Stein Olav Skrøvseth , Stephen D. Bartlett

We elaborate on the principle that for gapped quantum spin systems with local interaction "local perturbations [in the Hamiltonian] perturb locally [the ground state]". This principle was established in [Bachmann et al. 2012], relying on…

Mathematical Physics · Physics 2015-06-30 Wojciech De Roeck , Marius Schütz

While volume violation of area law has been exhibited in several quantum spin chains, the construction of a corresponding ground state in higher dimensions, entangled in more than one direction, has been an open problem. Here we construct a…

Quantum Physics · Physics 2024-10-16 Zhao Zhang , Israel Klich

Entanglement is one of the strongest quantum correlation, and is a key ingredient in fundamental aspects of quantum mechanics and a resource for quantum technologies. While entanglement theory is well settled for distinguishable particles,…

Quantum Physics · Physics 2021-08-27 Till Jonas Frederick Johann , Ugo Marzolino

Although the realization of useful quantum computers poses significant challenges, swift progress in emerging quantum technologies is making this goal realistically approachable. In this context, one of the essential resources is quantum…

Quantum Physics · Physics 2022-01-11 Valeria Saggio , Philip Walther

The Fermi-Hubbard model is of fundamental importance in condensed-matter physics, yet is extremely challenging to solve numerically. Finding the ground state of the Hubbard model using variational methods has been predicted to be one of the…

Quantum Physics · Physics 2021-01-04 Chris Cade , Lana Mineh , Ashley Montanaro , Stasja Stanisic

Recovering an unknown Hamiltonian from measurements is an increasingly important task for certification of noisy quantum devices and simulators. Recent works have succeeded in recovering the Hamiltonian of an isolated quantum system with…

Quantum Physics · Physics 2019-01-24 Eyal Bairey , Itai Arad , Netanel H. Lindner

Most states in the Hilbert space are maximally entangled. This fact has proven useful to investigate - among other things - the foundations of statistical mechanics. Unfortunately, most states in the Hilbert space of a quantum many body…

Quantum Physics · Physics 2015-05-30 Alioscia Hamma , Siddhartha Santra , Paolo Zanardi

The preparation and certification of quantum states is a fundamental challenge across quantum information technology. We introduce a tomography-free state certification method that lower-bounds the fidelity by estimating expectation values…

Localizability of entanglement in fully inseparable states is a key ingredient of assisted quantum information protocols as well as measurement-based models of quantum computing. We investigate the existence of fully inseparable states with…

Quantum Physics · Physics 2017-10-31 M. Mičuda , D. Koutný , M. Miková , I. Straka , M. Ježek , L. Mišta

Hamiltonian Learning (HL) is essential for validating quantum systems in quantum computing. Not all Hamiltonians can be uniquely recovered from a steady state. HL success depends on the Hamiltonian model and steady state. Here, we analyze…

Quantum Physics · Physics 2023-09-19 Jing Zhou , D. L. Zhou

Entanglement is the powerful and enigmatic resource central to quantum information processing, which promises capabilities in computing, simulation, secure communication, and metrology beyond what is possible for classical devices. Exactly…

In an important recent development, Anshu, Breuckmann, and Nirkhe [ABN22] resolved positively the so-called No Low-Energy Trivial State (NLTS) conjecture by Freedman and Hastings. The conjecture postulated the existence of linear-size local…

Quantum Physics · Physics 2024-11-20 Eric R. Anschuetz , David Gamarnik , Bobak Kiani