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Related papers: Certifying and learning local quantum Hamiltonians

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Many-body fermionic quantum calculations performed on analog quantum computers are restricted by the presence of k-local terms, which represent interactions among more than two qubits. These originate from the fermion-to-qubit mapping…

The problem of simulating sparse Hamiltonians on quantum computers is well studied. The evolution of a sparse N x N Hamiltonian H for time t can be simulated using O(||Ht||poly(log N)) operations, which is essentially optimal due to a…

Quantum Physics · Physics 2018-12-20 Andrew M. Childs , Robin Kothari

The complete learning of an $n$-qubit quantum state requires samples exponentially in $n$. Several works consider subclasses of quantum states that can be learned in polynomial sample complexity such as stabilizer states or high-temperature…

Quantum Physics · Physics 2023-09-19 Liming Zhao , Naixu Guo , Ming-Xing Luo , Patrick Rebentrost

We investigate quantum metrology using a Lie algebraic approach for a class of Hamiltonians, including local and nearest-neighbor interaction Hamiltonians. Using this Lie algebraic formulation, we identify and construct highly symmetric…

Quantum Physics · Physics 2015-08-26 Michalis Skotiniotis , Florian Fröwis , Wolfgang Dür , Barbara Kraus

The physics of quantum mechanics is the inspiration for, and underlies, quantum computation. As such, one expects physical intuition to be highly influential in the understanding and design of many quantum algorithms, particularly…

Quantum Physics · Physics 2017-01-06 Guang Hao Low , Isaac L. Chuang

We present an efficient method for estimating the eigenvalues of a Hamiltonian $H$ from the expectation values of the evolution operator for various times. For a given quantum state $\rho$, our method outputs a list of eigenvalue estimates…

Quantum Physics · Physics 2020-09-08 Rolando D. Somma

In this paper, we introduce Hamilton-Jacobi-Bellman (HJB) equations for Q-functions in continuous time optimal control problems with Lipschitz continuous controls. The standard Q-function used in reinforcement learning is shown to be the…

Optimization and Control · Mathematics 2020-05-05 Jeongho Kim , Insoon Yang

We show how one can asymptotically reach the Heisenberg limit in quantum Hamiltonian learning without entanglement, globally coherent measurements, or dynamical control, using only local quantum operations. Our protocol uses…

Quantum Physics · Physics 2025-12-02 Bora Baran , Timothy Heightman

We develop a resource efficient method by which the ground-state of an arbitrary k-local, optimization Hamiltonian can be encoded as the ground-state of a (k-1)-local optimization Hamiltonian. This result is important because adiabatic…

Quantum Physics · Physics 2014-10-16 Ryan Babbush , Bryan O'Gorman , Alán Aspuru-Guzik

Topologically ordered quantum matter exhibits intriguing long-range patterns of entanglement, which reveal themselves in subsystem entropies. However, measuring such entropies, which can be used to certify topological order, on large…

Quantum Physics · Physics 2024-08-26 Robert Ott , Torsten V. Zache , Nishad Maskara , Mikhail D. Lukin , Peter Zoller , Hannes Pichler

Data-driven extrapolation methods aim to extend the dynamics of quantum observables from measurements, but they often lack guarantees on prediction accuracy. We introduce a framework based on atomic norm minimization that can certify…

We consider the simulation of the dynamics of one nonlocal Hamiltonian by another, allowing arbitrary local resources but no entanglement nor classical communication. We characterize notions of simulation, and proceed to focus on…

Quantum Physics · Physics 2009-11-07 C. H. Bennett , J. I. Cirac , M. S. Leifer , D. W. Leung , N. Linden , S. Popescu , G. Vidal

Human experts cannot efficiently access the physical information of quantum many-body states by simply "reading" the coefficients, but have to reply on the previous knowledge such as order parameters and quantum measurements. In this work,…

Quantum Physics · Physics 2021-10-26 Xinran Ma , Z. C. Tu , Shi-Ju Ran

The commutator between operators at different space and time has been a diagnostic for locality of unitary evolution. Most existing results are either for specific tractable (random) Hamiltonians(Out-of-Time-Order-Correlators calculations),…

Quantum Physics · Physics 2021-03-17 Chi-Fang Chen

The exponential speedups promised by Hamiltonian simulation on a quantum computer depends crucially on structure in both the Hamiltonian $\hat{H}$, and the quantum circuit $\hat{U}$ that encodes its description. In the quest to better…

Quantum Physics · Physics 2017-07-19 Guang Hao Low , Isaac L. Chuang

The vast complexity is a daunting property of generic quantum states that poses a significant challenge for theoretical treatment, especially in non-equilibrium setups. Therefore, it is vital to recognize states which are locally less…

Quantum Physics · Physics 2022-07-28 Markus Schmitt , Zala Lenarčič

Solutions to many-body problem instances often involve an intractable number of degrees of freedom and admit no known approximations in general form. In practice, representing quantum-mechanical states of a given Hamiltonian using available…

Quantum Physics · Physics 2020-11-10 Andrey Kardashin , Alexey Uvarov , Dmitry Yudin , Jacob Biamonte

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

A fundamental task in quantum information science is state certification: testing whether a lab-prepared $n$-qubit state is close to a given hypothesis state. In this work, we show that every pure hypothesis state can be certified using…

Quantum Physics · Physics 2025-07-16 Meghal Gupta , William He , Ryan O'Donnell

The physics of a closed quantum mechanical system is governed by its Hamiltonian. However, in most practical situations, this Hamiltonian is not precisely known, and ultimately all there is are data obtained from measurements on the system.…

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