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Related papers: Fractional Control Gate Protocols For Quantum Engi…

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We explore the use of fractional control-not gates in quantum thermodynamics. The Nth-root gate allows for a paced application of two-qubit operations. We apply it in quantum thermodynamic protocols for charging a quantum battery. Circuits…

Quantum Physics · Physics 2024-11-12 Elliot Fox , Marcela Herrera , Ferdinand Schmidt-Kaler , Irene D'Amico

Building a quantum computer is a daunting challenge since it requires good control but also good isolation from the environment to minimize decoherence. It is therefore important to realize quantum gates efficiently, using as few operations…

Quantum Physics · Physics 2019-10-28 T. Bækkegaard , L. B. Kristensen , N. J. S. Loft , C. K. Andersen , D. Petrosyan , N. T. Zinner

Contemporary quantum computers encode and process quantum information in binary qubits (d = 2). However, many architectures include higher energy levels that are left as unused computational resources. We demonstrate a superconducting…

The question of whether quantum coherence is a resource beneficial or detrimental to the performance of quantum heat engines has been thoroughly studied but remains undecided. To isolate the contribution of coherence, we analyze the…

Quantum Physics · Physics 2023-02-01 Stefan Aimet , Hyukjoon Kwon

Quantum algorithms on near-term quantum processors are typically executed using shallow quantum circuits composed of one- and two-qubit gates. However, as circuit depth and gate number increase, gate imperfections and qubit decoherence…

While all quantum algorithms can be expressed in terms of single-qubit and two-qubit gates, more expressive gate sets can help reduce the algorithmic depth. This is important in the presence of gate errors, especially those due to…

Quantum coherence provides a controllable thermodynamic resource that can raise or lower the effective temperature of a cavity mode, enabling efficiency tuning in quantum heat engines. Here, we derive analytic expressions for the effective…

Quantum Physics · Physics 2026-04-07 Hui Wang , Yusef Maleki , William J. Munro , Marlan O. Scully

A clever choice and design of gate sets can reduce the depth of a quantum circuit, and can improve the quality of the solution one obtains from a quantum algorithm. This is especially important for near-term quantum computers that suffer…

Quantum Physics · Physics 2025-07-08 Madhav Mohan , Julius de Hond , Servaas Kokkelmans

In the task of unitarily cooling a quantum system with access to a larger quantum system, known as the machine or reservoir, how does the structure of the machine impact an agent's ability to cool and the complexity of their cooling…

Gate-based quantum computation has been extensively investigated using quantum circuits based on qubits. In many cases, such qubits are actually made out of multilevel systems but with only two states being used for computational purpose.…

Optimal control can be used to significantly improve multi-qubit gates in quantum information processing hardware architectures based on superconducting circuit quantum electrodynamics. We apply this approach not only to dispersive gates of…

Quantum Physics · Physics 2015-05-14 R. Fisher , F. Helmer , S. J. Glaser , F. Marquardt , T. Schulte-Herbrueggen

Starting with the basic control system model often employed in NMR pulse design, we derive more realistic control system models taking into account effects such as off-resonant excitation for systems with fixed inter-qubit coupling…

Quantum Physics · Physics 2009-10-01 Sonia Schirmer

Quantum logic gates must perform properly when operating on their standard input basis states, as well as when operating on complex superpositions of these states. Experiments using superconducting qubits have validated the truth table for…

An enduring challenge in computer science is reducing the runtime required to solve computational problems. Quantum computing has attracted significant attention due to its potential to deliver asymptotically faster solutions to certain…

Quantum Physics · Physics 2025-03-25 Mischa P. Woods

Non-equilibrium effects may have a profound impact on the performance of thermal devices performing thermodynamic tasks such as refrigeration or heat pumping. The possibility of enhancing the performance of thermodynamic operations by means…

Quantum Physics · Physics 2024-03-26 Kenza Hammam , Gonzalo Manzano , Gabriele De Chiara

Near-term hardware is constrained by high error rates, small qubit counts, and relatively low output fidelity, making the execution of large, high performance quantum circuits difficult. Circuit partitioning (or circuit cutting) has emerged…

Quantum Physics · Physics 2026-04-27 Connor Howe , Cristina Radian , Justin Woodring , Vardaan Sahgal , Brian J. McDermott

While the accuracy of qubit operations has been greatly improved in the last decade, further development is demanded to achieve the ultimate goal: a fault-tolerant quantum computer that can solve real-world problems more efficiently than…

Quantum Physics · Physics 2024-08-29 Kiyoto Nakamura , Joachim Ankerhold

The native gate set is fundamental to the performance of quantum devices, as it governs the accuracy of basic quantum operations and dictates the complexity of implementing quantum algorithms. Traditional approaches to extending gate sets…

We propose a two-qubit collisional phase gate that can be implemented with available atom chip technology, and present a detailed theoretical analysis of its performance. The gate is based on earlier phase gate schemes, but uses a qubit…

Recent studies have investigated the role of entanglement in the operation of a two-qubit system as a heat engine, showing that work can be extracted from a single heat bath without direct heat dissipation between the two-qubit system and…

Quantum Physics · Physics 2025-02-10 Hachem Tarif , Abdallah Slaoui , Rachid Ahl Laamara
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