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Related papers: Qubits in second quantisation in fermionic simulat…

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Advances in quantum technologies are often limited by slow device characterization, complex tuning requirements, and scalability challenges. Spin qubits in electrostatically defined quantum dots provide a promising platform but are not…

Variational quantum algorithms (VQAs) have been proposed as one of the most promising approaches to demonstrate quantum advantage on noisy intermediate-scale quantum (NISQ) devices. However, it has been unclear whether VQAs can maintain…

Quantum Physics · Physics 2022-11-15 Shigeo Hakkaku , Yuichiro Tashima , Kosuke Mitarai , Wataru Mizukami , Keisuke Fujii

We describe methods for simulating general second-quantized Hamiltonians using the compact encoding, in which qubit states encode only the occupied modes in physical occupation number basis states. These methods apply to second-quantized…

Quantum Physics · Physics 2022-06-29 William M. Kirby , Sultana Hadi , Michael Kreshchuk , Peter J. Love

Number-conserved subspace encoding reduces resources needed for quantum simulations, but scalable complexity trade-off bounds for $M$ modes and $N$ particles with $\mathcal{O}(N\log M)$ qubits have remained unknown. We study…

Quantum Physics · Physics 2025-09-23 M. H. Cheng , Yu-Cheng Chen , Qian Wang , V. Bartsch , M. S. Kim , Alice Hu , Min-Hsiu Hsieh

In recent years simulations of chemistry and condensed materials has emerged as one of the preeminent applications of quantum computing, offering an exponential speedup for the solution of the electronic structure for certain strongly…

Quantum Physics · Physics 2022-01-19 Torin F. Stetina , Anthony Ciavarella , Xiaosong Li , Nathan Wiebe

While many studies point towards the existence of many-body localization (MBL) in one dimension, the fate of higher-dimensional strongly disordered systems is a topic of current debate. The latest experiments as well as several recent…

Disordered Systems and Neural Networks · Physics 2024-05-13 Joey Li , Amos Chan , Thorsten B. Wahl

Simulating electronic structure on a quantum computer requires encoding of fermionic systems onto qubits. Common encoding methods transform a fermionic system of $N$ spin-orbitals into an $N$-qubit system, but many of the fermionic…

Quantum Physics · Physics 2022-06-07 Yu Shee , Pei-Kai Tsai , Cheng-Lin Hong , Hao-Chung Cheng , Hsi-Sheng Goan

Simulation of fermionic many-body systems on a quantum computer requires a suitable encoding of fermionic degrees of freedom into qubits. Here we revisit the Superfast Encoding introduced by Kitaev and one of the authors. This encoding maps…

Quantum Physics · Physics 2019-10-23 Kanav Setia , Sergey Bravyi , Antonio Mezzacapo , James D. Whitfield

We introduce a framework for simulating hybrid oscillator-qubit quantum processors on qubit-only systems through position encoding. By encoding continuous-variable position and momentum wave functions into qubit amplitudes, our method…

Quantum Physics · Physics 2026-03-11 Xi Lu , Bojko N. Bakalov , Yuan Liu

Many quantum algorithms, including recently proposed hybrid classical/quantum algorithms, make use of restricted tomography of the quantum state that measures the reduced density matrices, or marginals, of the full state. The most…

Quantum Physics · Physics 2018-05-16 Nicholas C. Rubin , Ryan Babbush , Jarrod McClean

Compact representations of fermionic Hamiltonians are necessary to perform calculations on quantum computers that lack error-correction. A fermionic system is typically defined within a subspace of fixed particle number and spin while…

Quantum Physics · Physics 2022-05-25 Diana Chamaki , Mekena Metcalf , Wibe A. de Jong

Compressible models extend the domain of simulable systems in quantum computers, but little is known about their precise limits of applicability. Using the theory of compressible matchgate circuits, we identify a class of quadratic…

Quantum Physics · Physics 2022-07-29 Guillermo Blázquez-Cruz , Pierre-Luc Dallaire-Demers

The construction of two-qubit gates appropriate for universal quantum computation is of enormous importance to quantum information processing. Building such gates is dependent on accurate knowledge of the interaction dynamics between two…

Quantum Physics · Physics 2009-11-11 Simon J. Devitt , Jared H. Cole , Lloyd C. L. Hollenberg

Simulating the real-time dynamics of lattice gauge theories, underlying the Standard Model of particle physics, is a notoriously difficult problem where quantum simulators can provide a practical advantage over classical approaches. In this…

Quantum Physics · Physics 2023-10-18 Torsten V. Zache , Daniel González-Cuadra , Peter Zoller

Introducing flexible native entanglement gates can significantly reduce circuit complexity. We propose a novel gate integrating iswap and cphase operations within a single gate cycle. We theoretically show one possible realization of this…

Quantum Physics · Physics 2025-10-01 Zhongyi Jiang , Mohammad H. Ansari

The simulation of quantum many-body systems, relevant for quantum chemistry and condensed matter physics, is one of the most promising applications of near-term quantum computers before fault-tolerance. However, since the vast majority of…

Quantum Physics · Physics 2025-10-20 Arash Jafarizadeh , Frank Pollmann , Adam Gammon-Smith

We propose a method for the efficient quantum simulation of fermionic systems with superconducting circuits. It consists in the suitable use of Jordan-Wigner mapping, Trotter decomposition, and multiqubit gates, be with the use of a quantum…

Quantum Physics · Physics 2015-04-01 U. Las Heras , L. García-Álvarez , A. Mezzacapo , E. Solano , L. Lamata

Quantum computers are inherently affected by noise. While in the long-term error correction codes will account for noise at the cost of increasing physical qubits, in the near-term the performance of any quantum algorithm should be tested…

A compelling application of quantum computers with thousands of qubits is quantum simulation. Simulating fermionic systems is both a problem with clear real-world applications and a computationally challenging task. In order to simulate a…

Quantum Physics · Physics 2026-02-27 Emiliia Dyrenkova , Raymond Laflamme , Michael Vasmer