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Related papers: 2-Local Hamiltonian with Low Complexity is QCMA

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Previously, all known variants of the Quantum Satisfiability (QSAT) problem, i.e. deciding whether a $k$-local ($k$-body) Hamiltonian is frustration-free, could be classified as being either in $\mathsf{P}$; or complete for $\mathsf{NP}$,…

Quantum Physics · Physics 2025-06-10 Ricardo Rivera Cardoso , Alex Meiburg , Daniel Nagaj

We review, restate, and prove a result due to Kaushal and Korsch [Phys. Lett. A 276, 47 (2000)] on the complete integrability of two-dimensional Hamiltonian systems whose Hamiltonian satisfies a set of four linear second order partial…

Mathematical Physics · Physics 2014-05-20 Ali Mostafazadeh

We study complexity of several problems related to the Transverse field Ising Model (TIM). First, we consider the problem of estimating the ground state energy known as the Local Hamiltonian Problem (LHP). It is shown that the LHP for TIM…

Quantum Physics · Physics 2017-01-12 Sergey Bravyi , Matthew Hastings

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

Understanding commuting local Hamiltonians (CLHs) is at the heart of many questions in quantum computational complexity and quantum physics: quantum error correcting codes, quantum NP, the PCP conjecture, topological order and more.

Quantum Physics · Physics 2013-01-16 Dorit Aharonov , Lior Eldar

Complexity of a quantum analogue of the satisfiability problem is studied. Quantum k-SAT is a problem of verifying whether there exists n-qubit pure state such that its k-qubit reduced density matrices have support on prescribed subspaces.…

Quantum Physics · Physics 2007-05-23 Sergey Bravyi

The Quantum Lov\'asz Local Lemma (QLLL) [AKS12] establishes non-constructively that any quantum system constrained by a local Hamiltonian has a zero-energy ground state, if the local Hamiltonian terms overlap only in a certain restricted…

Quantum Physics · Physics 2013-11-27 Martin Schwarz , Toby S. Cubitt , Frank Verstraete

Product states, unentangled tensor products of single qubits, are a ubiquitous ansatz in quantum computation, including for state-of-the-art Hamiltonian approximation algorithms. A natural question is whether we should expect to efficiently…

Quantum Physics · Physics 2025-02-12 John Kallaugher , Ojas Parekh , Kevin Thompson , Yipu Wang , Justin Yirka

We consider the computational complexity of Hamiltonians which are sums of commuting terms acting on plaquettes in a square lattice of qubits, and we show that deciding whether the ground state minimizes the energy of each local term…

Quantum Physics · Physics 2011-09-29 Norbert Schuch

The study of ground state energies of local Hamiltonians has played a fundamental role in quantum complexity theory. In this paper, we take a new direction by introducing the physically motivated notion of "ground state connectivity" of…

Quantum Physics · Physics 2019-01-08 Sevag Gharibian , Jamie Sikora

The NLTS (No Low-Energy Trivial State) conjecture of Freedman and Hastings [2014] posits that there exist families of Hamiltonians with all low energy states of high complexity (with complexity measured by the quantum circuit depth…

Quantum Physics · Physics 2022-12-14 Anurag Anshu , Nikolas P. Breuckmann

This paper investigates symmetric composite binary quantum hypothesis testing (QHT), where the goal is to determine which of two uncertainty sets contains an unknown quantum state. While asymptotic error exponents for this problem are…

Quantum Physics · Physics 2026-04-13 Jacob Paul Simpson , Efstratios Palias , Sharu Theresa Jose

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

We tackle the long-standing question of the computational complexity of determining homology groups of simplicial complexes, a fundamental task in computational topology, posed by Kaibel and Pfetsch 20 years ago. We show that this decision…

Quantum Physics · Physics 2024-11-27 Marcos Crichigno , Tamara Kohler

Commuting local Hamiltonians provide a testing ground for studying many of the most interesting open questions in quantum information theory, including the quantum PCP conjecture and the existence of area laws. Although they are a…

Quantum Physics · Physics 2025-04-08 John Bostanci , Yeongwoo Hwang

We elucidate the distinction between global and termwise stoquasticity for local Hamiltonians and prove several complexity results. We show that the stoquastic local Hamiltonian problem is $\textbf{StoqMA}$-complete even for globally…

Quantum Physics · Physics 2022-04-28 Marios Ioannou , Stephen Piddock , Milad Marvian , Joel Klassen , Barbara M. Terhal

Understanding the mechanisms responsible for the equilibration of isolated quantum many-body systems is a long-standing open problem. In this work we obtain a statistical relationship between the equilibration properties of Hamiltonians and…

Quantum Physics · Physics 2013-03-27 Lluis Masanes , Augusto J. Roncaglia , Antonio Acin

Finding a cycle of lowest weight that represents a homology class in a simplicial complex is known as homology localization (HL). Here we address this NP-complete problem using parameterized complexity theory. We show that it is W[1]-hard…

Computational Geometry · Computer Science 2020-12-01 Nello Blaser , Erlend Raa Vågset

The relative entropy between two states is a key concept in quantum information theory and quantum field theory. In the setting of quantum field theory, its computation requires the handling of relative modular Hamiltonians, which are…

Mathematical Physics · Physics 2026-05-27 Adriano Chialastri , Christoph Minz , Ko Sanders

StoqMA characterizes the computational hardness of stoquastic local Hamiltonians, which is a family of Hamiltonians that does not suffer from the sign problem. Although error reduction is commonplace for many complexity classes, such as…

Quantum Physics · Physics 2025-09-17 Dorit Aharonov , Alex B. Grilo , Yupan Liu