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Related papers: On complexity of the quantum Ising model

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We describe an efficient approximation algorithm for evaluating the ground-state energy of the classical Ising Hamiltonian with linear terms on an arbitrary planar graph. The running time of the algorithm grows linearly with the number of…

Quantum Physics · Physics 2009-09-16 Nikhil Bansal , Sergey Bravyi , Barbara M. Terhal

Stoquastic Hamiltonians are characterized by the property that their off-diagonal matrix elements in the standard product basis are real and non-positive. Many interesting quantum models fall into this class including the Transverse field…

Quantum Physics · Physics 2017-01-13 Sergey Bravyi

The calculation of ground-state energies of physical systems can be formalised as the k-local Hamiltonian problem, which is the natural quantum analogue of classical constraint satisfaction problems. One way of making the problem more…

Quantum Physics · Physics 2016-03-29 Toby Cubitt , Ashley Montanaro

The local Hamiltonian problem consists of estimating the ground-state energy (given by the minimum eigenvalue) of a local quantum Hamiltonian. First, we show the existence of a good product-state approximation for the ground-state energy of…

Quantum Physics · Physics 2016-02-04 Fernando G. S. L. Brandão , Aram W. Harrow

Determining properties of ground states of spin Hamiltonians remains a topic of central relevance connecting disciplines of mathematical, theoretical and applied physics. In the last few decades, ground state properties of physical systems…

Quantum Physics · Physics 2021-12-28 Jacob Biamonte

We consider the complexity of the local Hamiltonian problem in the context of fermionic Hamiltonians with $\mathcal N=2 $ supersymmetry and show that the problem remains $\mathsf{QMA}$-complete. Our main motivation for studying this is the…

Quantum Physics · Physics 2024-05-01 Chris Cade , P. Marcos Crichigno

Understanding the entanglement structure of local Hamiltonian ground spaces is a physically motivated problem, with applications ranging from tensor network design to quantum error-correcting codes. To this end, we study the complexity of…

Quantum Physics · Physics 2026-05-29 Sevag Gharibian , Jonas Kamminga

The k-local Hamiltonian problem is a natural complete problem for the complexity class QMA, the quantum analog of NP. It is similar in spirit to MAX-k-SAT, which is NP-complete for k<=2. It was known that the problem is QMA-complete for any…

Quantum Physics · Physics 2007-05-23 Julia Kempe , Alexei Kitaev , Oded Regev

It is known that three fundamental questions regarding local Hamiltonians -- approximating the ground state energy (the Local Hamiltonian problem), simulating local measurements on the ground space (APX-SIM), and deciding if the low energy…

Quantum Physics · Physics 2024-09-02 James D. Watson , Johannes Bausch , Sevag Gharibian

We introduce a quantum generalization of classical kinetic Ising models, described by a certain class of quantum many body master equations. Similarly to kinetic Ising models with detailed balance that are equivalent to certain Hamiltonian…

Quantum Physics · Physics 2015-05-14 R. Augusiak , F. M. Cucchietti , F. Haake , M. Lewenstein

Photonic Ising Machines constitute an emergent new paradigm of computation, geared towards tackling combinatorial optimization problems that can be reduced to the problem of finding the ground state of an Ising model. Spatial Photonic Ising…

The ground state energy and the free energy of Quantum Local Hamiltonians are fundamental quantities in quantum many-body physics, however, it is QMA-Hard to estimate them in general. In this paper, we develop new techniques to find…

Quantum Physics · Physics 2023-08-08 Thiago Bergamaschi

We propose a tensor-network (TN) approach for solving classical optimization problems that is inspired by spectral filtering and sampling on quantum states. We first shift and scale an Ising Hamiltonian of the cost function so that all…

Quantum Physics · Physics 2026-02-09 Ryo Watanabe , Joseph Tindall , Shohei Miyakoshi , Hiroshi Ueda

We prove that estimating the ground state energy of a translationally-invariant, nearest-neighbour Hamiltonian on a 1D spin chain is QMAEXP-complete, even for systems of low local dimension (roughly 40). This is an improvement over the best…

Quantum Physics · Physics 2017-11-15 Johannes Bausch , Toby Cubitt , Maris Ozols

Here we present a problem related to the local Hamiltonian problem (identifying whether the ground state energy falls within one of two ranges) which is restricted to being translationally invariant. We prove that for problems with a fixed…

Quantum Physics · Physics 2011-11-09 Alastair Kay

The partition function and free energy of a quantum many-body system determine its physical properties in thermal equilibrium. Here we study the computational complexity of approximating these quantities for $n$-qubit local Hamiltonians.…

Quantum Physics · Physics 2023-09-22 Sergey Bravyi , Anirban Chowdhury , David Gosset , Pawel Wocjan

We study several problems related to properties of non-negative matrices that arise at the boundary between quantum and classical probabilistic computation. Our results are twofold. First, we identify a large class of quantum Hamiltonians…

Quantum Physics · Physics 2010-01-22 Sergey Bravyi , Barbara Terhal

We estimate the resource requirements, the total number of physical qubits and computational time, required to compute the ground state energy of a 1-D quantum Transverse Ising Model (TIM) of N spin-1/2 particles, as a function of the…

Quantum Physics · Physics 2009-09-08 Craig R. Clark , Kenneth R. Brown , Tzvetan S. Metodi , Samuel D. Gasster

A systematic study of both classical and quantum geometric frustrated Ising models with a competing ordering mechanism is reported in this paper. The ordering comes in the classical case from a coupling of 2D layers and in the quantum model…

Statistical Mechanics · Physics 2007-05-23 Ying Jiang , Thorsten Emig

The QMA-completeness of the local Hamiltonian problem is a landmark result of the field of Hamiltonian complexity that studies the computational complexity of problems in quantum many-body physics. Since its proposal, substantial effort has…

Quantum Physics · Physics 2026-02-11 Asad Raza , Jens Eisert , Alex B. Grilo
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