English
Related papers

Related papers: Non-Hermitian Computers Need No Complex Numbers

200 papers

To implement a set of universal quantum logic gates based on non-Abelian geometric phases, it is a conventional wisdom that quantum systems beyond two levels are required, which is extremely difficult to fulfil for superconducting qubits,…

Quantum Physics · Physics 2015-08-12 Zheng-Yuan Xue , Jian Zhou , Z. D. Wang

In order for quantum computations to be done as efficiently as possible it is important to optimise the number of gates used in the underlying quantum circuits. In this paper we find that many gate optimisation problems for approximately…

Quantum Physics · Physics 2024-08-13 John van de Wetering , Matt Amy

Among the many proposals for the realization of a quantum computer, holonomic quantum computation (HQC) is distinguished from the rest in that it is geometrical in nature and thus expected to be robust against decoherence. Here we analyze…

Quantum Physics · Physics 2009-11-07 Antti O. Niskanen , Mikio Nakahara , Martti M. Salomaa

A new approach to efficient quantum computation with probabilistic gates is proposed and analyzed in both a local and non-local setting. It combines heralded gates previously studied for atom or atom-like qubits with logical encoding from…

Quantum Physics · Physics 2017-04-19 Johannes Borregaard , Anders S. Sørensen , Ignacio Cirac , Mikhail D. Lukin

Holonomic quantum computation exploits the geometric evolution of eigenspaces of a degenerate Hamiltonian to implement unitary evolution of computational states. In this work we introduce a framework for performing scalable quantum…

Quantum Physics · Physics 2026-04-29 Clara Wassner , Tommaso Guaita , Jens Eisert , Jose Carrasco

Recent works have shown that quantum computers can polynomially speed up certain SAT-solving algorithms even when the number of available qubits is significantly smaller than the number of variables. Here we generalise this approach. We…

Quantum Physics · Physics 2020-02-19 Yimin Ge , Vedran Dunjko

The presence of symmetries, be they discrete or continuous, in a physical system typically leads to a reduction in the problem to be solved. Here we report that neither translational invariance nor rotational invariance reduce the…

Quantum Physics · Physics 2008-07-24 Alastair Kay

We present a quantum algorithm which identifies with certainty a hidden subgroup of an arbitrary finite group G in only a polynomial (in log |G|) number of calls to the oracle. This is exponentially better than the best classical algorithm.…

Quantum Physics · Physics 2016-12-30 Mark Ettinger , Peter Hoyer , Emanuel Knill

A problem of universality in simulation of evolution of quantum system and in theory of quantum computations is related with the possibility of expression or approximation of arbitrary unitary transformation by composition of specific…

Quantum Physics · Physics 2009-11-06 Alexander Yu. Vlasov

Holonomic quantum computation is the idea to use non-Abelian geometric phases to implement universal quantum gates that are robust to fluctuations in control parameters. Here, we propose a compact design for a holonomic quantum computer…

Quantum Physics · Physics 2015-11-04 Zeynep Nilhan Gürkan , Erik Sjöqvist

Recently developed quantum algorithms suggest that quantum computers can solve certain problems and perform certain tasks more efficiently than conventional computers. Among other reasons, this is due to the possibility of creating…

Quantum Physics · Physics 2007-05-23 Rolando D. Somma

Quantum gates are the building blocks of quantum circuits, which in turn are the cornerstones of quantum information processing. In this work, we theoretically investigate a single-step implementation of both a universal two- (CNOT) and…

Quantum Physics · Physics 2024-07-01 Luiz O. R. Solak , Daniel Z. Rossatto , Celso J. Villas-Boas

Rig groupoids provide a semantic model of \PiLang, a universal classical reversible programming language over finite types. We prove that extending rig groupoids with just two maps and three equations about them results in a model of…

Programming Languages · Computer Science 2024-06-17 Jacques Carette , Chris Heunen , Robin Kaarsgaard , Amr Sabry

Holonomic Quantum Computation (HQC) is an all-geometrical approach to quantum information processing. In the HQC strategy information is encoded in degenerate eigen-spaces of a parametric family of Hamiltonians. The computational network of…

Quantum Physics · Physics 2009-11-06 Jiannis Pachos , Paolo Zanardi

The Hamiltonian H specifies the energy levels and the time evolution of a quantum theory. It is an axiom of quantum mechanics that H be Hermitian because Hermiticity guarantees that the energy spectrum is real and that the time evolution is…

Quantum Physics · Physics 2011-10-07 Carl M. Bender , Joachim Brod , Andre Refig , Moritz Reuter

A novel universal and fault-tolerant basis (set of gates) for quantum computation is described. Such a set is necessary to perform quantum computation in a realistic noisy environment. The new basis consists of two single-qubit gates…

Quantum Physics · Physics 2007-05-23 P. Oscar Boykin , Tal Mor , Matthew Pulver , Vwani Roychowdhury , Farrokh Vatan

Quantum canonical transformations of the second kind and the non-Hermitian realizations of the basic canonical commutation relations are investigated with a special interest in the generalization of the conventional ladder operators. The…

High Energy Physics - Theory · Physics 2009-10-28 W. S. l'Yi

We study the resources required to achieve universal quantum computing via the gate sets that provide the fundamental instructions from which quantum algorithms are built. While single-gate universal sets are known, they rely on precisely…

Quantum Physics · Physics 2026-02-24 Robin Kaarsgaard

We present a general technique to implement products of many qubit operators communicating via a joint harmonic oscillator degree of freedom in a quantum computer. By conditional displacements and rotations we can implement Hamiltonians…

Quantum Physics · Physics 2009-11-06 Xiaoguang Wang , Anders Sorensen , Klaus Molmer

We show the problem of counting homomorphisms from the fundamental group of a homology $3$-sphere $M$ to a finite, non-abelian simple group $G$ is #P-complete, in the case that $G$ is fixed and $M$ is the computational input. Similarly,…

Geometric Topology · Mathematics 2018-10-03 Greg Kuperberg , Eric Samperton