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Related papers: On complexity of the quantum Ising model

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In this work, we give a polynomial-time quantum algorithm for solving the ground states of a class of classically hard Hamiltonians. The mechanism of the exponential speedup that appeared in our algorithm comes from dissipation in open…

Quantum Physics · Physics 2024-11-13 Zhong-Xia Shang , Zi-Han Chen , Chao-Yang Lu , Jian-Wei Pan , Ming-Cheng Chen

We describe an algorithm that computes the ground state energy and correlation functions for 2-local Hamiltonians in which interactions between qubits are weak compared to single-qubit terms. The running time of the algorithm is polynomial…

Quantum Physics · Physics 2009-11-13 Sergey Bravyi , David DiVincenzo , Daniel Loss

Quantum annealers are an alternative approach to quantum computing which make use of the adiabatic theorem to efficiently find the ground state of a physically realizable Hamiltonian. Such devices are currently commercially available and…

Quantum Physics · Physics 2021-02-24 Justin Copenhaver , Adam Wasserman , Birgit Wehefritz-Kaufmann

Quantum Hamiltonian complexity studies computational complexity aspects of local Hamiltonians and ground states; these questions can be viewed as generalizations of classical computational complexity problems related to local constraint…

Quantum Physics · Physics 2015-03-17 Dorit Aharonov , Itai Arad , Zeph Landau , Umesh Vazirani

The area law for entanglement entropy fundamentally reflects the complexity of quantum many-body systems, demonstrating ground states of local Hamiltonians to be represented with low computational complexity. While this principle is…

Quantum Physics · Physics 2025-02-21 Donghoon Kim , Tomotaka Kuwahara

We perform a quantum simulation of the Ising model with a transverse field using a collection of three trapped atomic ion spins. By adiabatically manipulating the Hamiltonian, we directly probe the ground state for a wide range of fields…

Quantum Physics · Physics 2011-12-15 E. E. Edwards , S. Korenblit , K. Kim , R. Islam , M. -S. Chang , J. K. Freericks , G. -D. Lin , L. -M. Duan , C. Monroe

We propose a hybrid quantum-classical algorithm for approximating the ground state and ground state energy of a Hamiltonian. Once the Ansatz has been decided, the quantum part of the algorithm involves the calculation of two overlap…

Quantum Physics · Physics 2020-10-13 Kishor Bharti

We study classical polynomial-time approximation algorithms for the transverse-field Ising model (TFIM) Hamiltonian, allowing a mixture of ferromagnetic and anti-ferromagnetic interactions between pairs of qbits, alongside transverse field…

Quantum Physics · Physics 2026-01-22 Vincenzo Lipardi , David Mestel , Georgios Stamoulis

We study the computational complexity of 2-local Hamiltonian problems generated by a positive-weight symmetric interaction term, encompassing many canonical problems in statistical mechanics and optimization. We show these problems belong…

Quantum Physics · Physics 2026-04-15 Kunal Marwaha , James Sud

Given a Hamiltonian that is a sum of commuting few-body terms, the commuting Hamiltonian problem is to determine if there exists a quantum state that is the simultaneous eigenstate of all of these terms that minimizes each term…

Quantum Physics · Physics 2012-03-20 Jijiang Yan , Dave Bacon

Here we first discuss briefly the quantum annealing technique. We then study the quantum annealing of Sherrington-Kirkpatrick spin glass model with the tuning of both transverse and longitudinal fields. Both the fields are time-dependent…

Statistical Mechanics · Physics 2017-08-17 A Rajak , B K Chakrabarti

We propose a hybrid quantum-classical algorithm for approximating the ground state of two-dimensional quantum systems using an isometric tensor network ansatz, which maps naturally to quantum circuits. Inspired by the density matrix…

Achieving densely connected hardware graphs is a challenge for most quantum computing platforms today, and a particularly crucial one for the case of quantum annealing applications. In this context, we present a scalable architecture for…

Quantum Physics · Physics 2025-06-02 Ana Palacios , Artur Garcia-Saez , Bruno Julia-Diaz , Marta P. Estarellas

The Local Hamiltonian problem (finding the ground state energy of a quantum system) is known to be QMA-complete. The Local Consistency problem (deciding whether descriptions of small pieces of a quantum system are consistent) is also known…

Quantum Physics · Physics 2007-12-17 Yi-Kai Liu

We investigate the minimization of Ising Hamiltonians, comparing the performance of gain-based computing paradigms based on the dynamics of semi-classical soft-spin models with quantum annealing. We systematically analyze how the energy…

Quantum Physics · Physics 2025-02-17 James S. Cummins , Hayder Salman , Natalia G. Berloff

We study a finite spin-$\frac{1}{2}$ Ising chain with a spatially alternating transverse field of period 2. By means of a Jordan-Wigner transformation for even and odd sites, we are able to map it into a one-dimensional model of free…

Quantum Physics · Physics 2019-08-14 Adalberto D. Varizi , Raphael C. Drumond

Relations of simulated annealing and quantum annealing are studied by a mapping from the transition matrix of classical Markovian dynamics of the Ising model to a quantum Hamiltonian and vice versa. It is shown that these two operators, the…

Quantum Physics · Physics 2015-01-08 Hidetoshi Nishimori , Junichi Tsuda , Sergey Knysh

We relate a large class of classical spin models, including the inhomogeneous Ising, Potts, and clock models of q-state spins on arbitrary graphs, to problems in quantum physics. More precisely, we show how to express partition functions as…

Quantum Physics · Physics 2015-06-26 M. Van den Nest , W. Dür , H. J. Briegel

The canonical problem for the class Quantum Merlin-Arthur (QMA) is that of estimating ground state energies of local Hamiltonians. Perhaps surprisingly, [Ambainis, CCC 2014] showed that the related, but arguably more natural, problem of…

Quantum Physics · Physics 2022-10-18 Sevag Gharibian , Stephen Piddock , Justin Yirka

Ising machines (IM) are physics-inspired alternatives to von Neumann architectures for solving hard optimization tasks. By mapping binary variables to coupled Ising spins, IMs can naturally solve unconstrained combinatorial optimization…

Emerging Technologies · Computer Science 2025-08-01 Corentin Delacour