English
Related papers

Related papers: Fractional Control Gate Protocols For Quantum Engi…

200 papers

A challenge in building large-scale superconducting quantum processors is to find the right balance between coherence, qubit addressability, qubit-qubit coupling strength, circuit complexity and the number of required control lines. Leading…

Quantum Physics · Physics 2020-10-27 S. Krinner , P. Kurpiers , B. Royer , P. Magnard , I. Tsitsilin , J. -C. Besse , A. Remm , A. Blais , A. Wallraff

We analyze the optimal basis for generating the maximum relative entropy of quantum coherence by an arbitrary gate on a two-qubit system. The optimal basis is not unique, and the high quantum coherence generating gates are also typically…

Quantum Physics · Physics 2023-03-14 Aparajita Bhattacharyya , Ahana Ghoshal , Ujjwal Sen

Methods of optimal control are applied to a model system of interacting two-level particles (e.g., spin-half atomic nuclei or electrons or two-level atoms) to produce high-fidelity quantum gates while simultaneously negating the detrimental…

A limited number of qubits, high error rates, and limited qubit connectivity are major challenges for effective near-term quantum computations. Quantum circuit partitioning divides a quantum computation into a set of computations that…

Quantum Physics · Physics 2023-08-21 Sebastian Brandhofer , Ilia Polian , Kevin Krsulich

Quantum algorithm design usually assumes access to a perfect quantum computer with ideal properties like full connectivity, noise-freedom and arbitrarily long coherence time. In Noisy Intermediate-Scale Quantum (NISQ) devices, however, the…

Quantum Physics · Physics 2020-09-11 Xiangzhen Zhou , Sanjiang Li , Yuan Feng

The design space of current quantum computers is expansive with no obvious winning solution. This leaves practitioners with a clear question: "What is the optimal system configuration to run an algorithm?". This paper explores hardware…

Quantum Physics · Physics 2024-03-04 Justin Kalloor , Mathias Weiden , Ed Younis , John Kubiatowicz , Bert De Jong , Costin Iancu

In this study, we explore a relativistic quantum Otto heat engine with a qutrit as the working substance interacting with a quantum scalar field in curved spacetime. Unlike qubits, which extract work by simply expanding or shrinking a…

Quantum Physics · Physics 2025-07-01 Tomoya Hirotani , Kensuke Gallock-Yoshimura

Cloud-accessible quantum processors enable direct execution of quantum algorithms on heterogeneous hardware platforms. Unlike classical systems, however, identical quantum circuits may exhibit substantially different behavior across devices…

Quantum Physics · Physics 2026-01-12 Askar Oralkhan , Temirlan Zhaxalykov

We investigate, in an analytical fashion, quantum Carnot cycles of a microscopic heat engine coupled to two nite heat reservoirs, whose internal cycles could own higher e ciency than the standard Carnot limit without consuming extra quantum…

Statistical Mechanics · Physics 2024-09-04 L. -L. Yan , M. -R. Yun , M. Li , S. -L. Su , K. -F. Cui , Gang Chen , M. Feng

Universal quantum computing relies on high-fidelity entangling operations. Here we demonstrate that four coupled qubits can operate as a quantum gate, where two qubits control the operation on two target qubits (a four-qubit gate). This…

This dissertation explores quantum computation using qudits encoded into large spins, emphasizing the concept of quantum co-design to harness the unique capabilities of physical platforms for enhanced quantum information processing. First,…

Quantum Physics · Physics 2024-05-14 Sivaprasad Omanakuttan

Robust quantum computation with d-level quantum systems (qudits) poses two requirements: fast, parallel quantum gates and high fidelity two-qudit gates. We first describe how to implement parallel single qudit operations. It is by now well…

Quantum Physics · Physics 2009-11-13 Dianne P. O'Leary , Gavin K. Brennen , Stephen S. Bullock

The characterization and control of quantum effects in the performance of thermodynamic tasks may open new avenues for small thermal machines working in the nanoscale. We study the impact of coherence in the energy basis in the operation of…

Quantum Physics · Physics 2021-04-14 Kenza Hammam , Yassine Hassouni , Rosario Fazio , Gonzalo Manzano

This study presents a comparative analysis of three quantum thermal engines utilizing a two-qubit Heisenberg XXZ chain as the working substance. A novel generalized quantum Otto cycle (GQOC) is introduced, featuring two distinct coupling…

Quantum Physics · Physics 2025-03-28 Zorar Ahmadi , Bashir Mojaveri

Adiabatic geometric phase gates offer enhanced robustness against fluctuations compared to con- ventional Rydberg blockade-based phase gates that rely on dynamical phase accumulation. We theoretically demonstrate two- and multi-qubit phase…

Quantum Physics · Physics 2025-11-07 Sinchan Snigdha Rej , Bimalendu Deb

Quantum computation holds the promise of solving computational problems which are believed to be classically intractable. However, in practice, quantum devices are still limited by their relatively short coherence times and imperfect…

Quantum Physics · Physics 2023-12-22 Sagar Silva Pratapsi , Diogo Cruz

Realization of quantum computing requires the development of high-fidelity quantum gates that are resilient to decoherence, control errors, and environmental noise. While non-adiabatic holonomic quantum computation (NHQC) offers a promising…

Quantum Physics · Physics 2024-12-04 Zhihuang Kang , Shutong Wu , Kunji Han , Jiamin Qiu , Joel Moser , Jie Lu , Ying Yan

An open fully connected system of qubits at nonzero temperature is driven within a finite time interval along various paths in the space of its control parameters. The driving leads across finite-size precursors of first- and second-order…

Quantum Physics · Physics 2024-12-18 Felipe Matus , Pavel Cejnar

In this paper, we present the experimental realization of multi-qubit gates $% \Lambda_n(not) $ in macroscopic ensemble of three-qubit and four-qubit molecules. Instead of depending heavily on the two-bit universal gate, which served as the…

Quantum Physics · Physics 2009-11-06 J. F. Du , M. J. Shi , J. H. Wu , X. Y. Zhou , R. D. Han

In a quantum Stirling heat engine, the heat exchanged with two thermal baths is partly utilized for performing work by redistributing the energy levels of the working substance. We analyze the thermodynamics of a quantum Stirling engine…

Quantum Physics · Physics 2023-08-01 Debmalya Das , George Thomas , Andrew N. Jordan