Polynomial time algorithms for estimating spectra of adiabatic Hamiltonians

Journal Article · Mon Sep 30 00:00:00 EDT 2019 · Physical Review A

DOI:https://doi.org/10.1103/physreva.100.032336· OSTI ID:1613086

Bringewatt, Jacob ^[1]; Dorland, William ^[2]; Jordan, Stephen P. ^[3]

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1. Univ. of Maryland, College Park, MD (United States); Joint Center for Quantum Information and Computer Science, College Park, MD (United States); Joint Quantum Institute, College Park, MD (United States)
2. Univ. of Maryland, College Park, MD (United States)
3. Microsoft Quantum, Redmond, WA (United States); Univ. of Maryland Institute for Advanced Computer Studies, College Park, MD (United States)

Much research regarding quantum adiabatic optimization has focused on stoquastic Hamiltonians with Hamming-symmetric potentials, such as the well-studied “spike” example. Due to the large amount of symmetry in these potentials such problems are readily open to analysis both analytically and computationally. However, more realistic potentials do not have such a high degree of symmetry and may have many local minima. Here we present a somewhat more realistic class of problems consisting of many individually Hamming-symmetric potential wells. For two or three such wells we demonstrate that such a problem can be solved exactly in time polynomial in the number of qubits and wells. For greater than three wells, we present a tight-binding approach with which to efficiently analyze the performance of such Hamiltonians in an adiabatic computation. Here, we provide several basic examples designed to highlight the usefulness of this toy model and to give insight into using the tight-binding approach to examining it, including (1) an adiabatic unstructured search with a transverse field driver and a prior guess to the marked item and (2) a scheme for adiabatically simulating the ground states of small collections of strongly interacting spins, with an explicit demonstration for an Ising-model Hamiltonian.

• Research Organization: Univ. of Maryland, College Park, MD (United States); Krell Institute, Ames, IA (United States); Duke Univ., Durham, NC (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR); USDOE Office of Science (SC), Basic Energy Sciences (BES)
• Grant/Contract Number: SC0019040; SC0019323; SC0019449; SC0020312
• OSTI ID: 1613086
• Journal Information: Physical Review A, Vol. 100, Issue 3; ISSN 2469-9926
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
Optics
Physics
Adiabatic quantum optimization
Quantum algorithms