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Related papers: Unitarization of Pseudo-Unitary Quantum Circuits i…

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We report a deterministic and exact protocol to reverse any unknown qubit-unitary operation, which simulates the time inversion of a closed qubit system. To avoid known no-go results on universal deterministic exact unitary inversion, we…

Quantum Physics · Physics 2023-09-21 Satoshi Yoshida , Akihito Soeda , Mio Murao

Unitarity is a cornerstone of quantum theory, ensuring the conservation of probability and information. Although non-Hermitian Hamiltonians are typically associated with open or dissipative systems, pseudo-Hermitian quantum mechanics shows…

High Energy Physics - Theory · Physics 2025-11-03 Ruifeng Leng , Cheng-Yang Lee , Siyi Zhou

Quantum computing is powerful because unitary operators describing the time-evolution of a quantum system have exponential size in terms of the number of qubits present in the system. We develop a new "Singular value transformation"…

Quantum Physics · Physics 2020-02-21 András Gilyén , Yuan Su , Guang Hao Low , Nathan Wiebe

Pseudorandom circuits generate quantum states and unitary operators which are approximately distributed according to the unitarily invariant Haar measure. We explore how several design parameters affect the efficiency of pseudo-random…

Quantum Physics · Physics 2009-11-13 Yaakov S. Weinstein , Winton G. Brown , Lorenza Viola

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

Complex extension of quantum mechanics and the discovery of pseudo-unitarily invariant random matrix theory has set the stage for a number of applications of these concepts in physics. We briefly review the basic ideas and present…

Quantum Physics · Physics 2013-02-13 Shashi. C. L. Srivastava , S. R. Jain

A new generalized matrix inverse is derived which is consistent with respect to arbitrary nonsingular diagonal transformations, e.g., it preserves units associated with variables under state space transformations, thus providing a general…

Numerical Analysis · Mathematics 2026-04-02 Jeffrey Uhlmann

Semi-direct products of finite groups have permutation representations that are constructed from the permutation representations of their constituents. One can envision these in a metaphoric sense in which a rope is made from a bundle of…

Geometric Topology · Mathematics 2022-04-25 Yongju Bae , J. Scott Carter , Byeorhi Kim

We prove that there exist uniform $(+,\times,/)$-circuits of size $O(n^3)$ to compute the basis generating polynomial of regular matroids on $n$ elements. By tropicalization, this implies that there exist uniform $(\max,+,-)$-circuits and…

Combinatorics · Mathematics 2025-11-05 Christoph Hertrich , Stefan Kober , Georg Loho

For a unital ring $S$, an $S$-linear quasigroup is a unital $S$-module, with automorphisms $\rho$ and $\lambda$ giving a (nonassociative) multiplication $x\cdot y=x^\rho+y^\lambda$. If $S$ is the field of complex numbers, then ordinary…

Group Theory · Mathematics 2019-10-23 Jonathan D. H. Smith , Stefanie G. Wang

This work presents an optimization-based scalable quantum neural network framework for approximating $n$-qubit unitaries through generic parametric representation of unitaries, which are obtained as product of exponential of basis elements…

Quantum Physics · Physics 2024-01-17 Rohit Sarma Sarkar , Bibhas Adhikari

We analyze effective approximation of unitary matrices. In our formulation, a unitary matrix is represented as a product of rotations in two-dimensional subspaces, so-called Givens rotations. Instead of the quadratic dimension dependence…

Optimization and Control · Mathematics 2019-05-16 Thomas Frerix , Joan Bruna

We characterize the expressive power of quantum circuits with the pseudo-dimension, a measure of complexity for probabilistic concept classes. We prove pseudo-dimension bounds on the output probability distributions of quantum circuits; the…

Quantum Physics · Physics 2020-11-10 Matthias C. Caro , Ishaun Datta

We propose a new framework to represent the perturbative S-matrix which is well-defined for all quantum field theories of massless particles, constructed from tree-level amplitudes and integrable term-by-term. This representation is derived…

High Energy Physics - Theory · Physics 2016-02-17 Christian Baadsgaard , N. E. J. Bjerrum-Bohr , Jacob L. Bourjaily , Simon Caron-Huot , Poul H. Damgaard , Bo Feng

We give an algorithm for computing matrix corepresentations for special linear and special unitary quantum groups using a combinatorial re-indexing of basis elements.

Quantum Algebra · Mathematics 2008-09-19 Clark Alexander

Quantum operations on pure states can be fully represented by unitary matrices. Variational quantum circuits, also known as quantum neural networks, embed data and trainable parameters into gate-based operations and optimize the parameters…

Quantum Physics · Physics 2026-04-09 Basil Kyriacou , Mo Kordzanganeh , Maniraman Periyasamy , Alexey Melnikov

We propose a partial answer to the question of what kind of ultrahigh-energy physics has to be taken into account to circumvent the appearance of ultraviolet divergencies; a more than sixty years old open question in quantum…

General Physics · Physics 2007-05-23 Marijan Ribaric , Luka Sustersic

We introduce meta-factorization, a theory that describes matrix decompositions as solutions of linear matrix equations: the projector and the reconstruction equation. Meta-factorization reconstructs known factorizations, reveals their…

Numerical Analysis · Mathematics 2022-07-15 Michał P. Karpowicz

The method of multidimensional SUSY Quantum Mechanics is applied to the investigation of supersymmetrical N-particle systems on a line for the case of separable center-of-mass motion. New decompositions of the superhamiltonian into…

Quantum Physics · Physics 2008-11-26 M. V. Ioffe , A. I. Neelov

We consider a constructive modification of quantum-mechanical formalism. Replacement of a general unitary group by unitary representations of finite groups makes it possible to reproduce quantum formalism without loss of its empirical…

General Physics · Physics 2018-03-02 Vladimir V. Kornyak