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Related papers: Spin-Adapted Fermionic Unitaries: From Lie Algebra…

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Arbitrary exponentially large unitaries cannot be implemented efficiently by quantum circuits. However, we show that quantum circuits can efficiently implement any unitary provided it has at most polynomially many nonzero entries in any row…

Quantum Physics · Physics 2013-05-29 Stephen P. Jordan , Pawel Wocjan

Exactly-solvable Hamiltonians that can be diagonalized using relatively simple unitary transformations are of great use in quantum computing. They can be employed for decomposition of interacting Hamiltonians either in Trotter-Suzuki…

Quantum Physics · Physics 2023-09-19 Smik Patel , Tzu-Ching Yen , Artur F. Izmaylov

Quantum chemistry often considers atoms and molecules with non-zero spin. In such cases, the need for proper spin functions results in the theory of configuration state functions. Here, we consider the construction of such wavefunctions…

Chemical Physics · Physics 2019-04-25 Sahil Gulania , James Daniel Whitfield

We study the representation and visualization of finite-dimensional quantum systems. In a generalized Wigner representation, multi-spin operators can be decomposed into a symmetry-adapted tensor basis and they are mapped to multiple…

Quantum Physics · Physics 2020-11-30 David Leiner , Robert Zeier , Steffen J. Glaser

Simulating quantum dynamics on classical computers is challenging for large systems due to the significant memory requirements. Simulation on quantum computers is a promising alternative, but fully optimizing quantum circuits to minimize…

We investigate the simulation of fermionic systems on a quantum computer. We show in detail how quantum computers avoid the dynamical sign problem present in classical simulations of these systems, therefore reducing a problem believed to…

Condensed Matter · Physics 2009-02-05 G. Ortiz , J. E. Gubernatis , E. Knill , R. Laflamme

Many relevant applications of group theoretical methods to physical problems are related, in some manner, to classification schemes by means of symmetry groups. In these schemes, irreducible representations of a Lie group have to be…

High Energy Physics - Theory · Physics 2008-05-21 R. Campoamor-Stursberg

A central challenge in quantum simulation is to prepare low-energy states of strongly interacting many-body systems. In this work, we study the problem of preparing a quantum state that optimizes a random all-to-all, sparse or dense, spin…

Quantum Physics · Physics 2024-11-06 Joao Basso , Chi-Fang Chen , Alexander M. Dalzell

Using ultracold alkaline-earth atoms in optical lattices, we construct a quantum simulator for U(N) and SU(N) lattice gauge theories with fermionic matter based on quantum link models. These systems share qualitative features with QCD,…

Quantum Gases · Physics 2013-03-26 D. Banerjee , M. Bögli , M. Dalmonte , E. Rico , P. Stebler , U. -J. Wiese , P. Zoller

Both, spin and statistics of a quantum system can be seen to arise from underlying (quantum) group symmetries. We show that the spin-statistics theorem is equivalent to a unification of these symmetries. Besides covering the Bose-Fermi case…

High Energy Physics - Theory · Physics 2008-11-26 Robert Oeckl

Spectroscopic labels for a few particles with spin that are harmonically trapped in one-dimension with effectively zero-range interactions are provided by quantum numbers that characterize the symmetries of the Hamiltonian: permutations of…

Quantum Physics · Physics 2014-05-28 N. L. Harshman

Classical simulators play a major role in the development and benchmark of quantum algorithms and practically any software framework for quantum computation provides the option of running the algorithms on simulators. However, the…

Quantum Physics · Physics 2022-05-04 Gian Giacomo Guerreschi

Lattice gauge theories in varying dimensions, lattice volumes, and truncations offer a rich family of targets for Hamiltonian simulation on quantum devices. In return, formulating quantum simulations can provide new ways of thinking about…

Fermionic linear optics corresponds to the dynamics of free fermions, and is known to be efficiently simulable classically. We define fermionic anyon models by deforming the fermionic algebra of creation and annihilation operators, and…

Quantum Physics · Physics 2020-08-19 Allan D. C. Tosta , Daniel J. Brod , Ernesto F. Galvão

Performing large-scale, accurate quantum simulations of many-fermion systems is a central challenge in quantum science, with applications in chemistry, materials, and high-energy physics. Despite significant progress, realizing generic…

Quantum Physics · Physics 2025-09-12 Nishad Maskara , Marcin Kalinowski , Daniel Gonzalez-Cuadra , Mikhail D. Lukin

A widely used strategy to reduce the computational cost in quantum-chemical calculations is to partition the system into an active subsystem, which is the focus of the computational efforts and an environment that is treated at a lower…

Chemical Physics · Physics 2023-06-19 Elena Kolodzeiski , Christopher J. Stein

The most efficient known quantum circuits for preparing unitary coupled cluster states and applying Trotter steps of the arbitrary basis electronic structure Hamiltonian involve interleaved sequences of fermionic Gaussian circuits and Ising…

Quantum Physics · Physics 2021-09-13 Nicholas C. Rubin , Joonho Lee , Ryan Babbush

Constructing general programmable circuits to be able to run any given unitary operator efficiently on a quantum processor is of fundamental importance. We present a new quantum circuit design technique resulting two general programmable…

Quantum Physics · Physics 2012-07-24 Anmer Daskin , Ananth Grama , Giorgos Kollias , Sabre Kais

Quantum simulation algorithms often require numerous ancilla qubits and deep circuits, prohibitive for near-term hardware. We introduce a framework for simulating quantum channels using ensembles of low-depth circuits in place of many-qubit…

Quantum Physics · Physics 2024-08-01 Joseph Peetz , Scott E. Smart , Prineha Narang

The development of new electronic structure methods is a very time consuming and error prone process when done by hand. SpinAdaptedSecondQuantization is an open-source Julia package we have developed for working with automated electronic…

Chemical Physics · Physics 2025-08-26 Marcus T. Lexander , Tor S. Haugland , Federico Rossi , Henrik Koch