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Related papers: Cartan Decomposition of SU(2^n), Constructive Cont…

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Efficient decomposition of permutation unitaries is vital as they frequently appear in quantum computing. In this paper, we identify the key properties that impact the decomposition process of permutation unitaries. Then, we classify these…

Quantum Physics · Physics 2024-12-09 Ankit Khandelwal , Handy Kurniawan , Shraddha Aangiras , Özlem Salehi , Adam Glos

We present some compact quantum circuits for a deterministic quantum computing on electron-spin qubits assisted by quantum dots inside single-side optical microcavities, including the CNOT, Toffoli, and Fredkin gates. They are constructed…

Quantum Physics · Physics 2015-03-03 Hai-Rui Wei , Fu-Guo Deng

We introduce the notion of combinatorial gauge symmetry -- a local transformation that includes single spin rotations plus permutations of spins (or swaps of their quantum states) -- that preserve the commutation and anti-commutation…

Strongly Correlated Electrons · Physics 2020-08-11 Claudio Chamon , Dmitry Green , Zhi-Cheng Yang

We develop the concept of a unitary t-design as a means of expressing operationally useful subsets of the stochastic properties of the uniform (Haar) measure on the unitary group U(2^n) on n qubits. In particular, sets of unitaries forming…

Quantum Physics · Physics 2015-06-26 Christoph Dankert , Richard Cleve , Joseph Emerson , Etera Livine

We present an operational reconstruction of the well-known two-to-one homomorphism between the groups $SU(2)$ and $SO(3)$, grounded in the physical description of quantum state preparation and evolution. Starting from the connection between…

Quantum Physics · Physics 2025-12-02 V. G. Valle , B. F. Rizzuti

It is suggested to map the qubits into solid state NMR spin system collective states instead of the states of the individual spin. Such an approach introduces the stable computational basis without any additional actions and allows to…

Quantum Physics · Physics 2007-05-23 Alexander R. Kessel , Vladimir L. Ermakov

We show that a set of gates that consists of all one-bit quantum gates (U(2)) and the two-bit exclusive-or gate (that maps Boolean values $(x,y)$ to $(x,x \oplus y)$) is universal in the sense that all unitary operations on arbitrarily many…

Topological quantum computation may provide a robust approach for encoding and manipulating information utilizing the topological properties of anyonic quasi-particle excitations. We develop an efficient means to map between dense and…

Quantum Physics · Physics 2011-08-02 Haitan Xu , J. M. Taylor

One fundamental requirement for quantum computation is to perform universal manipulations of quantum bits at rates much faster than the qubit's rate of decoherence. Recently, fast gate operations have been demonstrated in logical spin…

Mesoscale and Nanoscale Physics · Physics 2010-09-28 Sandra Foletti , Hendrik Bluhm , Diana Mahalu , Vladimir Umansky , Amir Yacoby

Unitary transformations are the fundamental building blocks of gates and operations in quantum information processing allowing the complete manipulation of quantum systems in a coherent manner. In the case of photons, optical elements that…

Quantum Physics · Physics 2020-01-30 Florian Brandt , Markus Hiekkamäki , Frédéric Bouchard , Marcus Huber , Robert Fickler

We show that a wide range of spin clusters with antiferromagnetic intracluster exchange interaction allows one to define a qubit. For these spin cluster qubits, initialization, quantum gate operation, and readout are possible using the same…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Florian Meier , Jeremy Levy , Daniel Loss

Recently it has been shown that time-optimal quantum computation is attained by using the Cartan decomposition of a unitary matrix. We extend this approach by noting that the unitary group is compact. This allows us to reduce the execution…

Quantum Physics · Physics 2007-05-23 Mikio Nakahara , Juha J. Vartiainen , Yasushi Kondo , Shogo Tanimura , Kazuya Hata

We briefly review the spin-bit formalism, describing the non-planar dynamics of the $\mathcal{N}=4,d=4$ Super Yang-Mills SU(N) gauge theory. After considering its foundations, we apply such a formalism to the $su(2)$ sector of purely scalar…

High Energy Physics - Theory · Physics 2017-08-23 Alessio Marrani

To treat a problem with a Quantum Processing Unit (QPU), it must be transformed into a sequence of quantum operations, or gates: this is the quantum description of the problem. These operations are either packed into a query (i.e. quantum…

Quantum Physics · Physics 2026-03-19 Robin Ollive , Stéphane Louise

A rigid framework for the Cartan calculus of Lie derivatives, inner derivations, functions, and forms is proposed. The construction employs a semi-direct product of two graded Hopf algebras, the respective super-extensions of the deformed…

High Energy Physics - Theory · Physics 2008-02-03 Peter Schupp

Quantum control in large dimensional Hilbert spaces is essential for realizing the power of quantum information processing. For closed quantum systems the relevant input/output maps are unitary transformations, and the fundamental challenge…

Quantum Physics · Physics 2014-10-17 B. E. Anderson , H. Sosa-Martinez , C. A. Riofrío , I. H. Deutsch , P. S. Jessen

An arbitrary lossless transformation in high-dimensional quantum space can be decomposed into elementary operations which are easy to implement, and an effective decomposition algorithm is important for constructing high-dimensional…

Quantum Physics · Physics 2022-12-07 Dong-Xu Chen , Junliang Jia , Pei Zhang , Chui-Ping Yang

We provide new constructions of unitary $t$-designs for general $t$ on one qudit and $N$ qubits, and propose a design Hamiltonian, a random Hamiltonian of which dynamics always forms a unitary design after a threshold time, as a basic…

Quantum Physics · Physics 2017-04-25 Yoshifumi Nakata , Christoph Hirche , Masato Koashi , Andreas Winter

Simulating physical systems on near-term quantum computers often requires preparing states within constrained subspaces, like those with fixed particle number or spin. We use Lie algebraic techniques to prove that hardware-efficient gates…

Quantum Physics · Physics 2026-05-05 Andreas Stergiou , Nicolas PD Sawaya

In the 3rd episode of the serial exposition, quotient algebra partitions of rank zero earlier introduced undergo further partitions generated by bi-subalgebras of higher ranks. The refined versions of quotient algebra partitions admit not…

Mathematical Physics · Physics 2019-12-10 Zheng-Yao Su , Ming-Chung Tsai