English
Related papers

Related papers: Improved Approximations for Extremal Eigenvalues o…

200 papers

The $k$-local Hamiltonian problem is a central model for quantum many-body systems and Hamiltonian complexity. Semidefinite programming and noncommutative sum-of-squares hierarchies provide systematic certificates for ground-state energies,…

Quantum Physics · Physics 2026-05-29 Igor Klep , Nando Leijenhorst , Victor Magron

Predicting observables in equilibrium states is a central yet notoriously hard question in quantum many-body systems. In the physically relevant thermodynamic limit, certain mathematical formulations of this task have even been shown to…

Quantum Physics · Physics 2025-08-15 Hamza Fawzi , Omar Fawzi , Samuel O. Scalet

Simulation of quantum chemistry is expected to be a principal application of quantum computing. In quantum simulation, a complicated Hamiltonian describing the dynamics of a quantum system is decomposed into its constituent terms, where the…

Quantum Physics · Physics 2020-03-04 Yingkai Ouyang , David R. White , Earl T. Campbell

This work proposes a protocol for Fermionic Hamiltonian learning. For the Hubbard model defined on a bounded-degree graph, the Heisenberg-limited scaling is achieved while allowing for state preparation and measurement errors. To achieve…

Quantum Physics · Physics 2024-05-03 Hongkang Ni , Haoya Li , Lexing Ying

We provide a quantum algorithm for simulating the dynamics of sparse Hamiltonians with complexity sublogarithmic in the inverse error, an exponential improvement over previous methods. Specifically, we show that a $d$-sparse Hamiltonian $H$…

Quantum Physics · Physics 2014-10-09 Dominic W. Berry , Andrew M. Childs , Richard Cleve , Robin Kothari , Rolando D. Somma

The aim of this work is to extend the results from [B2] on local eigenvalue spacings to certain 1D lattice Schrodinger with a Bernoulli potential. We assume the disorder satisfies a certain algebraic condition that enables one to invoke the…

Analysis of PDEs · Mathematics 2013-08-22 Jean Bourgain

We present an efficient algorithm for simulating the time evolution due to a sparse Hamiltonian. In terms of the maximum degree d and dimension N of the space on which the Hamiltonian H acts for time t, this algorithm uses (d^2(d+log*…

Quantum Physics · Physics 2011-01-26 Andrew M. Childs , Robin Kothari

We present the saddle-point approximation for the effective Hamiltonian of the quantum kink in two-dimensional linear sigma models to all orders in the time-derivative expansion. We show how the effective Hamiltonian can be used to obtain…

High Energy Physics - Theory · Physics 2020-12-30 Ilarion V. Melnikov , Constantinos Papageorgakis , Andrew B. Royston

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

Quantum parameter estimation with Hermitian systems has been applied in various fields, but there are relatively few results concerning non-Hermitian systems. Here, we study the quantum parameter estimation for general non-Hermitian…

Quantum Physics · Physics 2023-09-06 Xinglei Yu , Chengjie Zhang

Hamiltonian Truncation Methods are a useful numerical tool to study strongly coupled QFTs. In this work we present a new method to compute the exact corrections, at any order, in the Hamiltonian Truncation approach presented by Rychkov et…

High Energy Physics - Theory · Physics 2016-05-25 J. Elias-Miro , M. Montull , M. Riembau

Approximation algorithms for classical constraint satisfaction problems are one of the main research areas in theoretical computer science. Here we define a natural approximation version of the QMA-complete local Hamiltonian problem and…

Quantum Physics · Physics 2016-10-25 Sevag Gharibian , Julia Kempe

To address quantum computation of quantities in quantum chromodynamics (QCD) for which chiral symmetry is important, it would be useful to have the Hamiltonian for a fermion satisfying the Ginsparg-Wilson (GW) equation. I work with an…

High Energy Physics - Lattice · Physics 2023-12-15 Michael Clancy

We show how to optimally reduce the local Hilbert basis of lattice quantum many-body (QMB) Hamiltonians. The basis truncation exploits the most relevant eigenvalues of the estimated single-site reduced density matrix (RDM). It is accurate…

Strongly Correlated Electrons · Physics 2025-09-23 Peter Majcen , Giovanni Cataldi , Pietro Silvi , Simone Montangero

We propose a computational protocol for quantum simulations of Fermionic Hamiltonians on a quantum computer, enabling calculations which were previously not feasible with conventional encoding and ansatses of variational quantum…

Quantum Physics · Physics 2023-03-15 Benchen Huang , Nan Sheng , Marco Govoni , Giulia Galli

We develop an efficient and robust approach to Hamiltonian identification for multipartite quantum systems based on the method of compressed sensing. This work demonstrates that with only O(s log(d)) experimental configurations, consisting…

Quantum Physics · Physics 2015-03-13 A. Shabani , M. Mohseni , S. Lloyd , R. L. Kosut , H. Rabitz

A candidate application for quantum computers is to simulate the low-temperature properties of quantum systems. For this task, there is a well-studied quantum algorithm that performs quantum phase estimation on an initial trial state that…

Quantum Physics · Physics 2024-11-04 Chi-Fang , Chen , Alexander M. Dalzell , Mario Berta , Fernando G. S. L. Brandão , Joel A. Tropp

Commuting Hamiltonians lie at the boundary between classical constraint satisfaction and quantum many-body physics, exhibiting rich quantum structure while remaining more tractable than general noncommuting models. In contrast, physical…

Quantum Physics · Physics 2026-05-26 Islam Faisal , Anand Natarajan , Alexander Poremba

Using the method of point canonical transformation, we derive some exactly solvable rationally extended quantum Hamiltonians which are non-Hermitian in nature and whose bound state wave functions are associated with Laguerre- or Jacobi-type…

Mathematical Physics · Physics 2012-11-08 Bikashkali Midya

In this work we will use a general procedure to construct higher local Hamiltonians for the affine $\mathfrak{sl}_2$ Gaudin model. We focus on the first non-trivial example, the quartic Hamiltonians. We show by direct calculation that the…

Quantum Algebra · Mathematics 2023-03-01 Tommaso Franzini , Charles A. S. Young