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Related papers: Fixed-Depth Two-Qubit Circuits and the Monodromy P…

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The Quadratic Assignment Problem (QAP) is a well-known NP-hard problem that is equivalent to optimizing a linear objective function over the QAP polytope. The QAP polytope with parameter $n$ - \qappolytope{n} - is defined as the convex hull…

Computational Complexity · Computer Science 2020-10-14 Pawan Aurora , Hans Raj Tiwary

Cavity-based large scale quantum information processing (QIP) may involve multiple cavities and require performing various quantum logic operations on qubits distributed in different cavities. Geometric-phase-based quantum computing has…

Quantum Physics · Physics 2016-03-15 Tong Liu , Xiao-Zhi Cao , Qi-Ping Su , Shao-Jie Xiong , Chui-Ping Yang

Modern quantum hardware exposes heterogeneous two-qubit instruction sets through fractional, continuously parameterized, and per-pair native gates, but synthesis remains largely framed around CNOT and a small catalog of closed-form rules.…

Quantum Physics · Physics 2026-05-07 Evan McKinney , Lev S. Bishop

Superconducting quantum devices are a leading technology for quantum computation, but they suffer from several challenges. Gate errors, coherence errors and a lack of connectivity all contribute to low fidelity results. In particular,…

Qubit-efficient optimization studies how large combinatorial problems can be addressed with quantum circuits whose width is far smaller than the number of logical variables. In quadratic unconstrained binary optimization (QUBO), objective…

Quantum Physics · Physics 2026-01-13 Gordon Ma , Dimitris G. Angelakis

Generic bifurcation theory was classically well developed for smooth differential systems, establishing results for $k$-parameter families of planar vector fields. In the present study we focus on a qualitative analysis of $2$-parameter…

Dynamical Systems · Mathematics 2018-09-11 Douglas Duarte Novaes , Marco Antonio Teixeira , Iris de Oliveira Zeli

The surface code is highly practical, enabling arbitrarily reliable quantum computation given a 2-D nearest-neighbor coupled array of qubits with gate error rates below approximately 1%. We describe an open source library, Polyestimate,…

Quantum Physics · Physics 2013-07-03 Austin G. Fowler

In a previous publication [1] we showed that it is possible to implement universal quantum computation with the anisotropic XY-Heisenberg exchange acting as a single interaction. To achieve this we used encodings of the states of the…

Quantum Physics · Physics 2009-11-07 J. Kempe , K. B. Whaley

The motivation for this paper is to study the complexity of constant-width arithmetic circuits. Our main results are the following. 1. For every k > 1, we provide an explicit polynomial that can be computed by a linear-sized monotone…

Computational Complexity · Computer Science 2009-08-14 V. Arvind , Pushkar S. Joglekar , Srikanth Srinivasan

In this work, we report on a novel quantum gate approximation algorithm based on the application of parametric two-qubit gates in the synthesis process. The utilization of these parametric two-qubit gates in the circuit design allows us to…

Quantum Physics · Physics 2022-11-16 Péter Rakyta , Zoltán Zimborás

In this paper, we study a class of fractional semi-infinite polynomial programming (FSIPP) problems, in which the objective is a fraction of a convex polynomial and a concave polynomial, and the constraints consist of infinitely many convex…

Optimization and Control · Mathematics 2021-05-18 Feng Guo , Liguo Jiao

Scaling up quantum computing hardware is hindered by the narrow operating margins of current quantum components. Here, we introduce a composite qubit and gate scheme that achieves wide margins by use of transistor-like nonlinearities to…

Quantum Physics · Physics 2022-02-23 Ryan J. Epstein

Implementations for quantum computing require fast single- and multi-qubit quantum gate operations. In the case of optically controlled quantum dot qubits theoretical designs for long-range two- or multi-qubit operations satisfying all the…

Mesoscale and Nanoscale Physics · Physics 2013-01-23 Dmitry Solenov , Sophia E. Economou , T. L. Reinecke

This paper explores the representation of quantum computing in terms of unitary reflections (unitary transformations that leave invariant a hyperplane of a vector space). The symmetries of qubit systems are found to be supported by…

Quantum Physics · Physics 2010-08-23 Michel Planat , Maurice R. Kibler

We present a framework based on the determinantal geometry of two-qubit gates. Combining the Weyl chamber representation with operator Schmidt theory, we interpret gate synthesis as a distance problem to determinantal varieties. This gives…

Quantum Physics · Physics 2026-04-17 Llorenç Balada Gaggioli

We theoretically investigate the use of fast pulsed two-qubit gates for trapped ion quantum computing in a two-dimensional microtrap architecture. In one dimension, such fast gates are optimal when employed between nearest neighbours, and…

Quantum Physics · Physics 2020-07-29 Zain Mehdi , Alexander K. Ratcliffe , Joseph J. Hope

We present two protocols for implementing deterministic non-local multi-qubit quantum gates on qubits coupled to a common cavity mode. The protocols rely only on a classical drive of the cavity modes, while no external drive of the qubits…

Quantum Physics · Physics 2025-03-24 Sven Jandura , Vineesha Srivastava , Laura Pecorari , Gavin Brennen , Guido Pupillo

We study non-local two-qubit operations from a geometric perspective. By applying a Cartan decomposition to su(4), we find that the geometric structure of non-local gates is a 3-Torus. We derive the invariants for local transformations, and…

Quantum Physics · Physics 2011-04-22 Jun Zhang , Jiri Vala , K. Birgitta Whaley , Shankar Sastry

We study efficient generations of random diagonal-unitary matrices, an ensemble of unitary matrices diagonal in a given basis with randomly distributed phases for their eigenvalues. Despite the simple algebraic structure, they cannot be…

Quantum Physics · Physics 2014-01-31 Yoshifumi Nakata , Mio Murao

The computational complexity of $\mathsf{QAC}^0$, which are constant-depth, polynomial-size quantum circuit families consisting of arbitrary single-qubit unitaries and $n$-qubit generalized Toffoli gates, has gained tremendous focus…

Quantum Physics · Physics 2026-04-09 Yangjing Dong , Fengning Ou , Penghui Yao