English
Related papers

Related papers: The Iterative Unitary Matrix Multiply Method and I…

200 papers

A random matrix is likely to be well conditioned, and motivated by this well known property we employ random matrix multipliers to advance some fundamental matrix computations. This includes numerical stabilization of Gaussian elimination…

Numerical Analysis · Mathematics 2012-12-27 Victor Y. Pan , Guoliang Qian

Extending our previous work on time optimal quantum state evolution, we formulate a variational principle for the time optimal unitary operation, which has direct relevance to quantum computation. We demonstrate our method with three…

Quantum Physics · Physics 2014-12-01 Alberto Carlini , Akio Hosoya , Tatsuhiko Koike , Yosuke Okudaira

The multiple-quantum operator algebra formalism has been exploited to construct generally an unsorted quantum search algorithm. The exponential propagator and its corresponding effective Hamiltonian are constructed explicitly that describe…

Quantum Physics · Physics 2007-05-23 Xijia Miao

Matrix-product states have become the de facto standard for the representation of one-dimensional quantum many body states. During the last few years, numerous new methods have been introduced to evaluate the time evolution of a…

Strongly Correlated Electrons · Physics 2019-11-15 Sebastian Paeckel , Thomas Köhler , Andreas Swoboda , Salvatore R. Manmana , Ulrich Schollwöck , Claudius Hubig

We present an improved version of commutator methods for unitary operators under a weak regularity condition. Once applied to a unitary operator, the method typically leads to the absence of singularly continuous spectrum and to the local…

Mathematical Physics · Physics 2011-12-02 C. Fernandez , S. Richard , R. Tiedra de Aldecoa

The experimental evaluation of many quantum mechanical quantities requires the estimation of several directly measurable observables, such as local observables. Due to the necessity to repeat experiments on individual quantum systems in…

Quantum Physics · Physics 2024-06-10 Ruidi Zhu , Ciara Pike-Burke , Florian Mintert

We introduce a constructive method for mapping non-unitary dynamics to a weighted set of unitary operations. We utilize this construction to derive a new correspondence between real and imaginary time, which we term Imaginary Time Quantum…

Quantum Physics · Physics 2024-09-11 Jacob M. Leamer , Alicia B. Magann , Denys I. Bondar , Gerard McCaul

Simulation of quantum matters is a significant application of quantum computers. In contrast to the unitary operation which can be realized naturally on a quantum computer, the implementation of nonunitary operation, widely used in…

Quantum Physics · Physics 2021-12-21 Tong Liu , Jin-Guo Liu , Heng Fan

In this paper we introduce an alternative approach to studying the evolution of a quantum harmonic oscillator subject to an arbitrary time dependent force. With the purpose of finding the evolution operator, certain unitary transformations…

For chaotic classical systems, the distribution of return times to a small region of phase space is universal. We propose a simple tool to investigate multiple returns in quantum systems. Numerical evidence for the baker map and kicked top…

Quantum Physics · Physics 2009-11-07 M. Fannes , P. Spincemaille

We apply the Quasi Monte Carlo (QMC) and recursive numerical integration methods to evaluate the Euclidean, discretized time path-integral for the quantum mechanical anharmonic oscillator and a topological quantum mechanical rotor model.…

High Energy Physics - Lattice · Physics 2016-01-26 A. Ammon , A. Genz , T. Hartung , K. Jansen , H. Leövey , J. Volmer

In a recent paper, Hassoul et al.[1], the authors proposed an analysis of the quantum dynamics for general time-dependent three coupled oscillators through an approach based on their decouplement using the unitary transformation method.…

Quantum Physics · Physics 2022-09-27 Zerimeche Rahma , Mana Naima , Maamache Mustapha

The resonant state of the open quantum system is studied from the viewpoint of the outgoing momentum flux. We show that the number of particles is conserved for a resonant state, if we use an expanding volume of integration in order to take…

Quantum Physics · Physics 2016-09-08 Naomichi Hatano , Keita Sasada , Hiroaki Nakamura , Tomio Petrosky

We introduce a variational quantum computing approach for quantum state reconstruction within a discretized logical framework, using experimental measurement data as input. By mapping the reconstruction cost function onto an Ising model,…

Quantum Physics · Physics 2026-04-03 Mwezi Koni , Shawal Kassim , Paola C. Obando , Neelan Gounden , Isaac Nape

We propose a quantum computer architecture which is robust against decoherence and scalable. As a qubit, we adopt rotational states of a nonpolar ionic molecule trapped in an ion-trap. It is revealed that the rotational-state qubits are…

Quantum Physics · Physics 2015-06-24 Sang Jae Yun , Chang Hee Nam

Quantum algorithms may be described by sequences of unitary transformations called quantum gates and measurements applied to the quantum register of n quantum bits, qubits. A collection of quantum gates is called universal if it can be used…

Quantum Physics · Physics 2007-05-23 M. Mottonen , J. J. Vartiainen

We describe a general methods to localize any sort of k-separability and therefore also the corresponding partial entanglement in genuinely multipartite mixed quantum states. Our methods are based exclusively on the known twopartite methods…

Quantum Physics · Physics 2010-03-02 Roman Gielerak Marek Sawerwain

This paper introduces a family of iterative algorithms for unconstrained nonlinear optimal control. We generalize the well-known iLQR algorithm to different multiple-shooting variants, combining advantages like straight-forward…

Systems and Control · Computer Science 2017-12-12 Markus Giftthaler , Michael Neunert , Markus Stäuble , Jonas Buchli , Moritz Diehl

We present a novel set of reversible modular multipliers applicable to quantum computing, derived from three classical techniques: 1) traditional integer division, 2) Montgomery residue arithmetic, and 3) Barrett reduction. Each multiplier…

Quantum Physics · Physics 2018-01-04 Rich Rines , Isaac Chuang

Quantum metrology involves the application of quantum resources to enhance measurements. Several communities have developed quantum-metrology strategies that leverage effective time reversals. These strategies, we posit, form four classes.…