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Related papers: Deciding universality of quantum gates

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In this research, we create a scalable version of the quantum Fourier transform-based arithmetic circuit to perform addition and subtraction operations on N n-bit unsigned integers encoded in quantum registers, and it is compatible with…

Quantum Physics · Physics 2024-11-04 Murat Kurt , Ayda Kaltehei , Azmi Gençten , Selçuk Çakmak

We perform optimal-control-theory calculations to determine the minimum number of two-qubit CNOT gates needed to perform quantum state preparation and unitary operator synthesis for few-qubit systems. By considering all possible gate…

Quantum Physics · Physics 2022-08-24 Sahel Ashhab , Naoki Yamamoto , Fumiki Yoshihara , Kouichi Semba

For certain quantum operations acting on qubits, there exist bases of measurement operators such that estimating the average fidelity becomes efficient. The number of experiments required is then independent of system size and the classical…

Quantum Physics · Physics 2014-09-15 Daniel M. Reich , Giulia Gualdi , Christiane P. Koch

We propose a universal gate set for quantum computing with all-to-all connectivity and intrinsic robustness to bit-flip errors based on parity encoding. We show that logical controlled phase gate and $R_z$ rotations can be implemented in…

Quantum Physics · Physics 2022-11-03 Michael Fellner , Anette Messinger , Kilian Ender , Wolfgang Lechner

Chern-Simons topological quantum computer is a device that can be effectively described by the Chern-Simons topological quantum field theory and used for quantum computations. Quantum qudit gates of this quantum computer are represented by…

High Energy Physics - Theory · Physics 2022-02-10 Nikita Kolganov , Sergey Mironov , Andrey Morozov

Optimizing the size and depth of CNOT circuits is an active area of research in quantum computing and is particularly relevant for circuits synthesized from the Clifford + T universal gate set. Although many techniques exist for finding…

Quantum Physics · Physics 2025-07-15 Alan Bu , Evan Fan , Robert Sanghyeon Joo

We provide a method for compiling approximate multi-controlled single qubit gates into quantum circuits without ancilla qubits. The total number of elementary gates to decompose an n-qubit multi-controlled gate is proportional to 32n, and…

In this paper, we develop a Lie group theoretic approach for parametric representation of unitary matrices. This leads to develop a quantum neural network framework for quantum circuit approximation of multi-qubit unitary gates. Layers of…

Quantum Physics · Physics 2025-03-26 Rohit Sarma Sarkar , Bibhas Adhikari

A recurrence scheme is presented to decompose an $n$-qubit unitary gate to the product of no more than $N(N-1)/2$ single qubit gates with small number of controls, where $N = 2^n$. Detailed description of the recurrence steps and formulas…

Quantum Physics · Physics 2013-12-06 Chi-Kwong Li , Diane Pelejo

We study optimal perfect distinguishability between a unitary and a general quantum operation. In 2-dimensional case we provide a simple sufficient and necessary condition for sequential perfect distinguishability and an analytical formula…

Quantum Physics · Physics 2010-10-13 Cheng Lu , Jianxin Chen , Runyao Duan

Optimal implementation of quantum gates is crucial for designing a quantum computer. We consider the matrix representation of an arbitrary multiqubit gate. By ordering the basis vectors using the Gray code, we construct the quantum circuit…

Quantum Physics · Physics 2007-05-23 Juha J. Vartiainen , Mikko Mottonen , Martti M. Salomaa

We consider the Unitary Permutation problem which consists, given $n$ unitary gates $U_1, \ldots, U_n$ and a permutation $\sigma$ of $\{1,\ldots, n\}$, in applying the unitary gates in the order specified by $\sigma$, i.e. in performing…

Quantum Physics · Physics 2016-10-11 Stefano Facchini , Simon Perdrix

Quantum computation provides great speedup over its classical counterpart for certain problems. One of the key challenges for quantum computation is to realize precise control of the quantum system in the presence of noise. Control of the…

Quantum Physics · Physics 2015-11-30 Xing Rong , Jianpei Geng , Fazhan Shi , Ying Liu , Kebiao Xu , Wenchao Ma , Fei Kong , Zhen Jiang , Yang Wu , Jiangfeng Du

Any unitary transformation of quantum computational networks is explicitly decomposed, in an exact and unified form, into a sequence of a limited number of one-qubit quantum gates and the two-qubit diagonal gates that have diagonal unitary…

Quantum Physics · Physics 2007-05-23 Xijia Miao

While the question ``how many CNOT gates are needed to simulate an arbitrary two-qubit operator'' has been conclusively answered -- three are necessary and sufficient -- previous work on this topic assumes that one wants to simulate a given…

Quantum Physics · Physics 2007-05-23 Vivek V. Shende , Igor L. Markov

This paper proposes a new optimized quantum block-ZXZ decomposition method [7,8,10] that results in more optimal quantum circuits than the quantum Shannon decomposition (QSD)[27], which was introduced in 2006 by Shende et al. The…

Quantum Physics · Physics 2024-04-04 Anna M. Krol , Zaid Al-Ars

Quantized integrable systems can be made to perform universal quantum computation by the application of a global time-varying control. The action-angle variables of the integrable system function as qubits or qudits, which can be coupled…

Quantum Physics · Physics 2014-08-05 Seth Lloyd , Simone Montangero

Universal gate sets for quantum computation, when single and two qubit operations are accessible, include both Hermitian and non-Hermitian gates. Here we utilize the fact that any single-qubit operator may be implemented as two Hermitian…

Quantum Physics · Physics 2025-12-03 Ben Zindorf , Sougato Bose

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

We present some deterministic schemes to construct universal quantum gates, that is, controlled- NOT, three-qubit Toffoli, and Fredkin gates, between flying photon qubits and stationary electron-spin qubits assisted by quantum dots inside…

Quantum Physics · Physics 2015-06-12 Hai-Rui Wei , Fu-Guo Deng