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Related papers: Building Qutrit Diagonal Gates from Phase Gadgets

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We develop an angular momentum representation and implementation of the Clifford+T set of unitaries for qutrits. We show that local gates from this set can be realized by the sole use of suitable rotations and one-axis-twisting operations,…

Quantum Physics · Physics 2026-04-28 F. E. S. Steinhoff

We present a way to realize a $n$-qubit controlled phase gate with superconducting quantum interference devices (SQUIDs) by coupling them to a superconducting resonator. In this proposal, the two logical states of a qubit are represented by…

Quantum Physics · Physics 2009-11-11 Chui-Ping Yang , Siyuan Han

Three-qubit gates can be constructed using combinations of single-qubit and two-qubit gates, making their independent realization unnecessary. However, direct implementation of three-qubit gates reduces the depth of quantum circuits,…

The Clifford hierarchy is a nested sequence of sets of quantum gates critical to achieving fault-tolerant quantum computation. Diagonal gates of the Clifford hierarchy and 'nearly diagonal' semi-Clifford gates are particularly important:…

Quantum Physics · Physics 2021-09-15 Nadish de Silva

Although qubits are the leading candidate for the basic elements in a quantum computer, there are also a range of reasons to consider using higher dimensional qudits or quantum continuous variables (QCVs). In this paper we use a general…

Quantum Physics · Physics 2017-05-11 Timothy Proctor , Melissa Giulian , Natalia Korolkova , Erika Andersson , Viv Kendon

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…

Motivated for the fault tolerant quantum computation, quantum gate by adiabatic geometric phase shift is extensively investigated. In this paper, we demonstrate the nonadiabatic scheme for the geometric phase shift and conditional geometric…

Quantum Physics · Physics 2007-05-23 Wang Xiang-Bin , Matsumoto Keiji

Multi-qubit parity measurements are at the core of many quantum error correction schemes. Extracting multi-qubit parity information typically involves using a sequence of multiple two-qubit gates. In this paper, we propose a superconducting…

Quantum Physics · Physics 2023-04-11 Kasper Sangild Christensen , Nikolaj Thomas Zinner , Morten Kjaergaard

Resource consumption is an important issue in quantum information processing, particularly during the present NISQ era. In this paper, we investigate resource optimization of implementing multiple controlled operations, which are…

Quantum Physics · Physics 2024-02-08 Junhong Nie , Wei Zi , Xiaoming Sun

Circuit design based on Quantum-dots Cellular Automata technology offers power-efficiency and nano-size circuits. It is an attractive alternative to CMOS technology. The XOR gate is a widely used building element in arithmetic circuits. An…

Emerging Technologies · Computer Science 2024-12-30 Behrouz Safaiezadeh , Majid Haghparast , Lauri Kettunen

Tunable couplers have recently become one of the most powerful tools for implementing two-qubit gates between superconducting qubits. A tunable coupler typically includes a nonlinear element, such as a SQUID, which is used to tune the…

We present a way to realize a 3-qubit quantum controlled-phase gate with superconducting qubit systems coupled to a cavity. This proposal does not require adjustment of the qubit level spacings or identical qubit-cavity coupling constants.…

Quantum Physics · Physics 2017-02-01 Chui-Ping Yang

Recent hardware demonstrations and advances in circuit compilation have made quantum computing with higher-dimensional systems (qudits) on near-term devices an attractive possibility. Some problems have more natural or optimal encodings…

Quantum Physics · Physics 2023-08-17 Gabriel Bottrill , Mudit Pandey , Olivia Di Matteo

We present improved circuits for the control-control-phase (Toffoli) gate and the control-swap (Fredkin) gate using three and four global two-qubit gates, respectively. This is a nearly double speed-up compared to the conventional circuits,…

Quantum Physics · Physics 2015-03-19 Svetoslav S. Ivanov , Peter A. Ivanov , Nikolay V. Vitanov

The ZX-calculus is an intuitive but also mathematically strict graphical language for quantum computing, which is especially powerful for the framework of quantum circuits. Completeness of the ZX-calculus means any equality of matrices with…

Quantum Physics · Physics 2023-05-18 Quanlong Wang

In this paper, we study the optimal simulation of three-qubit unitary by using two-qubit gates. First, we give a lower bound on the two-qubit gates cost of simulating a multi-qubit gate. Secondly, we completely characterize the two-qubit…

Quantum Physics · Physics 2013-01-17 Nengkun Yu , Mingsheng Ying

Quantum circuit network is a set of circuits that implements a certain computation task. Being at the center of the quantum circuit network, the multi-qubit controlled phase shift is one of the most important quantum gates. In this paper,…

Quantum Physics · Physics 2009-11-10 Jingfu Zhang , Wenzhang Liu , Zhiwei Deng , Zhiheng Lu , Gui Lu Long

In this work, we introduce a general n-qubit formulation of control objectives that allows a control target to be specified in a diagonal frame, so that only the diagonal entries must be characterized, thus quadratically reducing the…

Quantum Physics · Physics 2026-02-23 Bora Baran , Tommaso Calarco , Matthias M. Mueller , Felix Motzoi

Qudit-based quantum gates offer several advantages over qubit-based counterparts, such as higher information density, the ability to address more complex problems, and richer quantum operations. In this paper, we present three realistic…

Quantum Physics · Physics 2025-05-15 Zhi-Guo Fan , Zhuo-Ya Bai , Qiu-Lin Tan , Fang-Fang Du

The ZH-calculus is a graphical calculus for linear maps between qubits that allows a natural representation of the Toffoli+Hadamard gate set. The original version of the calculus, which allows every generator to be labelled by an arbitrary…

Quantum Physics · Physics 2019-04-17 John van de Wetering , Sal Wolffs