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Related papers: Unitary Coupled Cluster: Seizing the Quantum Momen…

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We study the low energy states of finite spin chains with isotropic (Heisenberg) and anisotropic (XY and Ising-like) exchange interaction with uniform and non-uniform coupling constants. We show that for an odd number of sites a spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Florian Meier , Jeremy Levy , Daniel Loss

We apply the quantum optimal control theory based on the Krotov method to implement single-qubit $X$ and $Z$ gates and two-qubit CNOT gates for inductively coupled superconducting flux qubits with fixed qubit transition frequencies and…

Quantum Physics · Physics 2014-07-16 Shang-Yu Huang , Hsi-Sheng Goan

We introduce a multicomponent unitary coupled cluster framework for quantum simulations of molecular systems that incorporate both electronic and nuclear quantum effects beyond the Born-Oppenheimer approximation. Using the…

Modern platforms for potential qubit candidates, such as trapped ions or neutral atoms, allow long range connectivity between distant physical qubits through shuttling. This opens up an avenue for transversal logical CNOT gates between…

Quantum Physics · Physics 2025-04-14 Kwok Ho Wan , Mark Webber , Austin G. Fowler , Winfried K. Hensinger

Quantum computing is a promising technology that harnesses the peculiarities of quantum mechanics to deliver computational speedups for some problems that are intractable to solve on a classical computer. Current generation noisy…

Numerical Analysis · Mathematics 2022-09-16 Daan Camps , Efekan Kökcü , Lindsay Bassman , Wibe A. de Jong , Alexander F. Kemper , Roel Van Beeumen

We present the quantum-selected configuration interaction-tailored coupled-cluster (QSCI-TCC) method, a hybrid quantum-classical scheme that tailors coupled-cluster (CC) theory with a quantum-selected configuration interaction (QSCI) wave…

Chemical Physics · Physics 2025-06-23 Luca Erhart , Yuichiro Yoshida , Wataru Mizukami

We combine classical heuristics with partial shadow tomography to enable efficient protocols for extracting information from correlated ab initio electronic systems encoded on quantum devices. By proposing the use of a correlation energy…

We propose a noise-mitigation quantum simulation strategy for near-term quantum devices based on Quantum Circuit Learning (QCL), which is in particular effective for integrable quantum spin chains. The method trains a shallow variational…

Quantum Physics · Physics 2026-05-01 Wenlong Zhao , Yimeng Zhang , Yan Guo , Yufan Cui , Zhuohang Wang , Rui-Dong Zhu

We calculate steady-state properties of a strongly correlated quantum dot under voltage bias by means of non-equilibrium Cluster Perturbation Theory and the non-equilibrium Variational Cluster Approach, respectively. Results for the…

Strongly Correlated Electrons · Physics 2013-01-15 Martin Nuss , Christoph Heil , Martin Ganahl , Michael Knap , Hans Gerd Evertz , Enrico Arrigoni , Wolfgang von der Linden

Limited quantum memory is one of the most important constraints for near-term quantum devices. Understanding whether a small quantum computer can simulate a larger quantum system, or execute an algorithm requiring more qubits than…

Quantum Physics · Physics 2020-12-10 Tianyi Peng , Aram Harrow , Maris Ozols , Xiaodi Wu

Quantum machine learning deals with leveraging quantum theory with classic machine learning algorithms. Current research efforts study the advantages of using quantum mechanics or quantum information theory to accelerate learning time or…

Quantum Physics · Physics 2025-09-03 Javier Orduz , Pablo Rivas , Erich Baker

In this brief paper, we go through the theoretical steps of the spectral clustering on quantum computers by employing the phase estimation and the amplitude amplification algorithms. We discuss circuit designs for each step and show how to…

Quantum Physics · Physics 2017-07-24 Ammar Daskin

Adaptive quantum circuits employ unitary gates assisted by mid-circuit measurement, classical computation on the measurement outcome, and the conditional application of future unitary gates based on the result of the classical computation.…

Planning energy production is a challenging task due to its cost-sensitivity, fast-moving energy markets, uncertainties in demand, and technical constraints of power plants. Thus, more complex models of this so-called \emph{unit commitment…

Quantum Physics · Physics 2024-03-07 Pascal Halffmann , Patrick Holzer , Kai Plociennik , Michael Trebing

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

Quantum error correcting codes have been developed to protect a quantum computer from decoherence due to a noisy environment. In this paper, we present two methods for optimizing the physical implementation of such error correction schemes.…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Guido Burkard , Daniel Loss , David P. DiVincenzo , John A. Smolin

Modelling non-linear activation functions on quantum computers is vital for quantum neurons employed in fully quantum neural networks, however, remains a challenging task. We introduce an amplitude-based implementation for approximating…

Quantum Physics · Physics 2023-02-09 Jonas Koppe , Mark-Oliver Wolf

It is known that if the quantum gates in a proposed quantum computer are so noisy that they are incapable of generating entanglement, then the device can be efficiently simulated classically. If the measurements and single particle…

Quantum Physics · Physics 2012-01-04 N. Ratanje , S. Virmani

Quantum error correction is vital for implementing universal quantum computing. A key component is the encoding circuit that maps a product state of physical qubits into the encoded multipartite entangled logical state. Known methods are…

Quantum Physics · Physics 2021-04-07 Xiaosi Xu , Simon C. Benjamin , Xiao Yuan

Classical simulations of noisy quantum circuits are instrumental to our understanding of the behavior of real-world quantum systems and the identification of regimes where one expects quantum advantage. In this work, we present a highly…

Quantum Physics · Physics 2026-02-17 Simon Cichy , Paul K. Faehrmann , Lennart Bittel , Jens Eisert , Hakop Pashayan