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It is believed that the presence of anticrossings with exponentially small gaps between the lowest two energy levels of the system Hamiltonian, can render adiabatic quantum optimization inefficient. Here, we present a simple adiabatic…

Quantum Physics · Physics 2013-05-30 Neil G. Dickson , Mohammad H. Amin

According to the quantum adiabatic theorem, we can in principle obtain a true vacuum of a quantum system starting from a trivial vacuum of a simple Hamiltonian. In actual adiabatic digital quantum simulation with finite time length and…

Quantum Physics · Physics 2022-04-11 Kazuto Oshima

We introduce the idea of using adiabatic rotation to generate superpositions of a large class of quantum states. For quantum computing this is an interesting alternative to the well-studied "straight line" adiabatic evolution. In ways that…

Quantum Physics · Physics 2009-11-13 M. Stewart Siu

We introduce an algorithm to perform an optimal adiabatic evolution that operates without an apriori knowledge of the system spectrum. By probing the system gap locally, the algorithm maximizes the evolution speed, thus minimizing the total…

Quantum Physics · Physics 2011-05-10 J. Nehrkorn , S. Montangero , A. Ekert , A. Smerzi , R. Fazio , T. Calarco

Quantum adiabatic algorithm is a method of solving computational problems by evolving the ground state of a slowly varying Hamiltonian. The technique uses evolution of the ground state of a slowly varying Hamiltonian to reach the required…

Quantum Physics · Physics 2015-06-26 Avik Mitra , Arindam Ghosh , Ranabir Das , Apoorva Patel , Anil Kumar

It is known that for multi-level time-dependent quantum systems one can construct superadiabatic representations in which the coupling between separated levels is exponentially small in the adiabatic limit. For a family of two-state systems…

Mathematical Physics · Physics 2009-11-10 Volker Betz , Stefan Teufel

We introduce a simple framework for estimating lower bounds on the runtime of a broad class of adiabatic quantum algorithms. The central formula consists of calculating the variance of the final Hamiltonian with respect to the initial…

Quantum Physics · Physics 2024-02-13 Jyong-Hao Chen

We introduce and study the adiabatic dynamics of free-fermion models subject to a local Lindblad bath and in the presence of a time-dependent Hamiltonian. The merit of these models is that they can be solved exactly, and will help us to…

Quantum Physics · Physics 2017-11-20 Maximilian Keck , Simone Montangero , Giuseppe E. Santoro , Rosario Fazio , Davide Rossini

Adiabatic quantum computation (AQC) is a universal model for quantum computation which seeks to transform the initial ground state of a quantum system into a final ground state encoding the answer to a computational problem. AQC initial…

Quantum Physics · Physics 2010-01-29 Alejandro Perdomo , Salvador E. Venegas-Andraca , Alán Aspuru-Guzik

One of the goals in quantum simulation is to adiabatically generate the ground state of a complicated Hamiltonian by starting with the ground state of a simple Hamiltonian and slowly evolving the system to the complicated one. If the…

Quantum Physics · Physics 2015-08-24 Bryce Yoshimura , J. K. Freericks

The theoretical investigation of non-adiabatic processes is hampered by the complexity of the coupled electron-nuclear dynamics beyond the Born-Oppenheimer approximation. Classically, the simulation of such reactions is limited by the…

Quantum Physics · Physics 2021-01-06 Pauline J. Ollitrault , Guglielmo Mazzola , Ivano Tavernelli

We generalize the adiabatic approximation to the case of open quantum systems, in the joint limit of slow change and weak open system disturbances. We show that the approximation is ``physically reasonable'' as under wide conditions it…

Quantum Physics · Physics 2016-08-16 Patrik Thunström , Johan Åberg , Erik Sjöqvist

We propose a quantum algorithm for solving combinatorial search problems that uses only a sequence of measurements. The algorithm is similar in spirit to quantum computation by adiabatic evolution, in that the goal is to remain in the…

We propose a technique for design of quantum Fourier transforms, and ensuing quantum algorithms, in a single interaction step by engineered Hamiltonians of circulant symmetry. The method uses adiabatic evolution and is robust against…

Quantum Physics · Physics 2009-10-07 B. T. Torosov , N. V. Vitanov

Quantum computation has revolutionary potential for speeding algorithms and for simulating quantum systems such as molecules. We report here a quantum computer design that performs universal quantum computation within a single…

Quantum Physics · Physics 2014-01-22 Ari Mizel

Quantum adiabatic evolution provides a general technique for the solution of combinatorial search problems on quantum computers. We present the results of a numerical study of a particular application of quantum adiabatic evolution, the…

Quantum Physics · Physics 2018-12-20 Andrew M. Childs , Edward Farhi , Jeffrey Goldstone , Sam Gutmann

We present a rigorous proof that quantum circuit algorithm can be transformed into quantum adiabatic algorithm with the exact same time complexity. This means that from a quantum circuit algorithm of $L$ gates we can construct a quantum…

Quantum Physics · Physics 2018-10-24 Hongye Yu , Yuliang Huang , Biao Wu

The adiabatic theorem provides the basis for the adiabatic model of quantum computation. Recently the conditions required for the adiabatic theorem to hold have become a subject of some controversy. Here we show that the reported violations…

Quantum Physics · Physics 2013-05-29 M. H. S. Amin

We study a simple system described by a 2x2 Hamiltonian and the evolution of the quantum states under the influence of a perturbation. More precisely, when the initial Hamiltonian is not degenerate,we check analytically the validity of the…

Strongly Correlated Electrons · Physics 2011-02-28 Christian Brouder , Gabriel Stoltz , Gianluca Panati

The ability to efficiently prepare ground states of quantum Hamiltonians via adiabatic protocols is typically limited by the smallest energy gap encountered during the quantum evolution. This presents a key obstacle for quantum simulation…