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Related papers: Accelerating Quantum Optimal Control of Multi-Qubi…

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Quadratic Unconstrained Binary Optimization (QUBO) is a broad class of optimization problems with many practical applications. To solve its hard instances in an exact way, known classical algorithms require exponential time and several…

Quantum Physics · Physics 2021-01-21 Gian Giacomo Guerreschi

We describe and demonstrate a method for the computation of quantum dynamics on small, noisy universal quantum computers. This method relies on the idea of `restarting' the dynamics; at least one approximate time step is taken on the…

Quantum Physics · Physics 2019-10-15 Matthew Otten , Cristian L. Cortes , Stephen K. Gray

We present a method to experimentally realize large-scale permutation-symmetric Hamiltonians for continuous-time quantum protocols such as quantum walk and adiabatic quantum computation. In particular, the method can be used to perform an…

Quantum Physics · Physics 2019-09-18 Ben Dodds , Viv Kendon , Charles S. Adams , Nicholas Chancellor

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

Medium-scale quantum devices that integrate about hundreds of physical qubits are likely to be developed in the near future. However, such devices will lack the resources for realizing quantum fault tolerance. Therefore, the main challenge…

Quantum Physics · Physics 2021-12-24 Chao Song , Jing Cui , H. Wang , J. Hao , H. Feng , Ying Li

In this letter, we present an experimental benchmark of operational control methods in quantum information processors extended up to 12 qubits. We implement universal control of this large Hilbert space using two complementary approaches…

Digital-analog quantum computing is a computational paradigm which employs an analog Hamiltonian resource together with single-qubit gates to reach universality. Here, we design a new scheme which employs an arbitrary two-body source…

This work focuses on optimizing the gates of a quantum circuit with a given topology to approximate the unitary time evolution governed by a Hamiltonian. Recognizing that unitary matrices form a mathematical manifold, we employ Riemannian…

Quantum Physics · Physics 2025-07-01 Fabian Putterer , Max M. Zumpe , Isabel Nha Minh Le , Qunsheng Huang , Christian B. Mendl

Quantum arithmetic computation requires a substantial number of scratch qubits to stay reversible. These operations necessitate qubit and gate resources equivalent to those needed for the larger of the input or output registers due to state…

Quantum Physics · Physics 2025-07-21 Omid Faizy , Norbert Wehn , Paul Lukowicz , Maximilian Kiefer-Emmanouilidis

Circuit QED enables the combined use of qubits and oscillator modes. Despite a variety of available gate sets, many hybrid qubit-boson (i.e., oscillator) operations are realizable only through optimal control theory (OCT) which is…

Quantum Physics · Physics 2025-01-08 Christopher Kang , Micheline B. Soley , Eleanor Crane , S. M. Girvin , Nathan Wiebe

Practical applicability of quantum optimisation on near term devices is constrained by limited qubit counts and hardware noise, which restricts the scalability of quantum optimisation algorithms for combinatorial problems. The simulation of…

Quantum Physics · Physics 2026-05-01 Namasi G Sankar , Georgios Miliotis , Simon Caton

We present a quantum algorithm for finding the minimum of a function based on multistep quantum computation and apply it for optimization problems with continuous variables, in which the variables of the problem are discretized to form the…

Quantum Physics · Physics 2023-07-03 Hefeng Wang , Hua Xiang

The exploration of neural network quantum states has become widespread in the studies of complicated quantum many-body systems. However, achieving high precision remains challenging due to the exponential growth of Hilbert space size and…

Strongly Correlated Electrons · Physics 2025-04-22 Shuai-Tin. Bao , Dian Wu , Pan Zhang , Ling Wang

Optimizing over separable quantum objects is challenging for two key reasons: determining separability is NP-hard, and the dimensionality of the problem grows exponentially with the number of qubits. We address both challenges by…

Quantum Physics · Physics 2025-10-01 Ankith Mohan , Tobias Haug , Kishor Bharti , Jamie Sikora

Simulating Hamiltonian dynamics is one of the most fundamental and significant tasks for characterising quantum materials. Recently, a series of quantum algorithms employing block-encoding of Hamiltonians have succeeded in providing…

Quantum Physics · Physics 2023-01-18 Kaoru Mizuta

Quantum-circuit optimization is essential for any practical realization of quantum computation, in order to beat decoherence. We present a scheme for implementing the final stage in the compilation of quantum circuits, i.e., for finding the…

Quantum Physics · Physics 2007-05-23 Juha J. Vartiainen , Antti O. Niskanen , Mikio Nakahara , Martti M. Salomaa

We consider a bipartite quantum object, composed of a quantum system and a quantum actuator which is periodically reset. We show that the reduced dynamics of the system approaches unitarity as the reset frequency of the actuator is…

Quantum Physics · Physics 2016-04-05 David Layden , Eduardo Martin-Martinez , Achim Kempf

We propose a hybrid quantum-classical eigensolver to address the computational challenges of simulating strongly correlated quantum many-body systems, where the exponential growth of the Hilbert space and extensive entanglement render…

Quantum Physics · Physics 2025-10-23 Lei Xu , Ling Wang

We describe criteria for implementation of quantum computation in qudits. A qudit is a d-dimensional system whose Hilbert space is spanned by states |0>, |1>,... |d-1>. An important earlier work of Mathukrishnan and Stroud [1] describes how…

Quantum Physics · Physics 2009-11-10 Gavin K. Brennen , Dianne P. O'Leary , Stephen S. Bullock

Advancing quantum technologies requires precise and robust coherent control of quantum systems. Robust higher-order Hamiltonian engineering is essential for high-precision control and for accessing effective dynamics absent at zeroth order.…

Quantum Physics · Physics 2026-03-13 Jiahui Chen , David Cory