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Related papers: Quantum Circuits and Spin(3n) Groups

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We study quantum systems with even numbers N of levels that are completely state-controlled by unitary transformations generated by Lie algebras isomorphic to sp(N) of dimension N(N+1)/2. These Lie algebras are smaller than the respective…

Quantum Physics · Physics 2009-11-13 R. Cabrera , C. Rangan , W. E. Baylis

A crucial requirement for quantum information processing is the realization of multiple-qubit quantum gates. Here, we demonstrate an electron spin based all-electrical two-qubit gate consisting of single spin rotations and inter-dot spin…

Quantum Physics · Physics 2015-05-30 R. Brunner , Y. -S. Shin , T. Obata , M. Pioro-Ladrière , T. Kubo , K. Yoshida , T. Taniyama , Y. Tokura , S. Tarucha

We propose a universal set of single- and two-qubit quantum gates acting on a hybrid qubit formed by coupling a quantum dot spin qubit to a $\mathbb{Z}_{2m}$ parafermion qubit with arbitrary integer $m$. The special case $m=1$ reproduces…

Mesoscale and Nanoscale Physics · Physics 2024-06-03 Denis V. Kurlov , Melina Luethi , Anatoliy I. Lotkov , Katharina Laubscher , Jelena Klinovaja , Daniel Loss

Computations with a future quantum computer will be implemented through the operations by elementary quantum gates. It is now well known that the collection of 1-bit and 2-bit quantum gates are universal for quantum computation, i.e., any…

Quantum Physics · Physics 2007-05-23 G. Chen , D. A. Church , B. -G. Englert , M. S. Zubairy

Quantum computation and quantum simulation require a versatile gate set to optimize circuit compilation for practical applications. However, existing platforms are often limited to specific gate types or rely on parametric couplers to…

Quantum Physics · Physics 2026-02-03 Guangze Chen , Anton Frisk Kockum

Clifford algebras are used for definition of spinors. Because of using spin-1/2 systems as an adequate model of quantum bit, a relation of the algebras with quantum information science has physical reasons. But there are simple mathematical…

Quantum Physics · Physics 2007-05-23 Alexander Yu. Vlasov

Simulating large-scale coupled-oscillator systems presents substantial computational challenges for classical algorithms, particularly when pursuing first-principles analyses in the thermodynamic limit. Motivated by the quantum algorithm…

Increasing the quantum information processing power with limited number of hosts is vital for achieving quantum advantage. Here we propose a novel scheme that achieves a scalable n-ion-2n-qubit quantum processor utilizing four internal…

Quantum Physics · Physics 2024-07-02 Ji Bian , Teng Liu , Qifeng Lao , Min Ding , Huiyi Zhang , Xinxin Rao , Pengfei Lu , Le Luo

In quantum circuits, qubits and the quantum gates acting on them have traditionally been analysed using matrix algebra and Dirac notation. While powerful, these can be unintuitive for conceptual understanding and rapid problem solving. In…

Physics Education · Physics 2025-03-21 Serkan Akkoyun

In this paper, we exclusively utilize CNOT gates for implementing permutation groups generated by more than two elements. In Lemma 1, we recall that three CNOT gates are both necessary and sufficient to execute a two-qubit swap gate…

Quantum Physics · Physics 2024-06-04 Junchi Liu , Yangyang Ren , Yan Cao , Hanyi Sun , Lin Chen

A proof is given, which relies on the commutator algebra of the unitary Lie groups, that quantum gates operating on just two bits at a time are sufficient to construct a general quantum circuit. The best previous result had shown the…

Condensed Matter · Physics 2009-10-22 David P. Divincenzo

Variational algorithms require architectures that naturally constrain the optimization space to run efficiently. Geometric quantum machine learning achieves this goal by encoding group structure into parameterized quantum circuits to…

Quantum Physics · Physics 2026-03-25 Richard D. P. East , Guillermo Alonso-Linaje , Chae-Yeun Park

Lattice gauge theories in varying dimensions, lattice volumes, and truncations offer a rich family of targets for Hamiltonian simulation on quantum devices. In return, formulating quantum simulations can provide new ways of thinking about…

Understanding which subclasses of quantum circuits are efficiently classically simulable is fundamental to delineating the boundary between classical and quantum computation. In this context, it is well known that certain tasks based on…

Quantum Physics · Physics 2026-03-16 Su Yeon Chang , Martin Larocca , M. Cerezo

A quantum circuit is generalized to a nonunitary one whose constituents are nonunitary gates operated by quantum measurement. It is shown that a specific type of one-qubit nonunitary gates, the controlled-NOT gate, as well as all one-qubit…

Quantum Physics · Physics 2011-01-11 Hiroaki Terashima , Masahito Ueda

Quantum computation using electron spins in three coupled dot with different size is proposed. By using the energy selectivity of both photon assisted tunneling and spin rotation of electrons, logic gates are realized by static and…

Quantum Physics · Physics 2007-05-23 H. Sasakura , S. Muto

Spin network states are a powerful tool for constructing the $SU(2)$ gauge theories on a graph. In loop quantum gravity (LQG), they have yielded many promising predictions, although progress has been limited by the computational challenge…

General Relativity and Quantum Cosmology · Physics 2023-04-10 Grzegorz Czelusta , Jakub Mielczarek

It is shown that anisotropic spin chains with gapped bulk excitations and magnetically ordered ground states offer a promising platform for quantum computation, which bridges the conventional single-spin-based qubit concept with recently…

Mesoscale and Nanoscale Physics · Physics 2011-10-14 Yaroslav Tserkovnyak , Daniel Loss

The spin states of single electrons in gate-defined quantum dots satisfy crucial requirements for a practical quantum computer. These include extremely long coherence times, high-fidelity quantum operation, and the ability to shuttle…

This work proposes numerical tests which determine whether a two-qubit operator has an atypically simple quantum circuit. Specifically, we describe formulae, written in terms of matrix coefficients, characterizing operators implementable…

Quantum Physics · Physics 2009-11-10 Vivek V. Shende , Stephen S. Bullock , Igor L. Markov