Computational Physics
Research: QUANTUM COMPUTATION

Quantum circuit-based computation


Picture showing the scaling properties of a Massively Parallel Quantum Computer Simulator

On a circuit-based quantum computer a computation is decomposed into a sequence of a few-qubit quantum gates. This type of quantum computer operates by changing its state through the application of unitary transformations. However, the ideal transformations used in most theoretical work are difficult to implement on a physical realization of a quantum computer. Therefore it is important to investigate the functioning of quantum computer hardware under non-ideal conditions. Our quantum computer emulators solve the time-dependent Schrödinger equation of ideal and realistic quantum models of quantum computer hardware and are therefore well-suited to address this important issue.

Quantum Computer Emulator (QCE)

QCE is a software tool that emulates various hardware designs of Quantum Computers.QCE simulates the physical processes that govern the operation of a hardware quantum processor, strictly according to the laws of quantum mechanics. QCE also provides an environment to debug and execute quantum algorithms under realistic experimental conditions. The software consists of a Graphical User Interface (GUI) and the simulator itself.
QCE can be downloaded from here.

Adiabatic quantum computation

On an adiabatic quantum computer a computation is decomposed into a slow continuous transformation of an initial Hamiltonian into a final Hamiltonian, whose ground state contains the solution. An adiabatic quantum computer relies on the adiabatic theorem to do calculations.

Selected publications:
  • T. Neuhaus, M. Peschina, K. Michielsen, and H. De Raedt,
    "Classical and quantum annealing in the median of three-satisfiability",
    Phys. Rev. A 83, 012309 (2011)
    PDF
  • K. De Raedt, K. Michielsen, H. De Raedt, B. Trieu, G. Arnold, M. Richter, Th. Lippert, H. Watanabe, N. Ito,
    "Massively Parallel Quantum Computer Simulator",
    Comp. Phys. Comm. 176, 121 - 136 (2007)
    PDF
  • H. De Raedt and K. Michielsen,
    "Computational Methods for Simulating Quantum Computers",
    Handbook of Theoretical and Computational Nanotechnology, Vol. 3: Quantum and molecular computing, quantum simulations,
    Chapter 1, pp. 248, M. Rieth and W. Schommers eds., American Scientific Publisher, Los Angeles (2006)
    PDF
  • K.F.L. Michielsen and H.A. De Raedt,
    "QCE: A Simulator for Quantum Computer Hardware",
    Turk. J. Phys. 27, 343 - 370 (2003)
    PDF
  • K. Michielsen, H. De Raedt, and K. De Raedt,
    "A simulator for quantum computer hardware",
    NanoTechnology 13, 23 - 28 (2002)
    PDF
  • H. De Raedt, K. Michielsen, A. Hams, S. Miyashita, K. Saito,
    "Quantum spin dynamics as a model for quantum computer operation",
    Eur. Phys. J. B27, 15 - 28 (2002)
    PDF
  • H. De Raedt, K. Michielsen, K. De Raedt, and S. Miyashita,
    "Number partitioning on a quantum computer"
    Phys. Lett. A 290, 227 - 233 (2001)
    PDF
  • H. De Raedt, A.H. Hams, K. Michielsen, K. De Raedt,
    "Quantum Computer Emulator",
    Comp. Phys. Comm. 132, 1 - 20 (2000)
    PDF
Presentations:
  • QCE: A Simulator for Quantum Computer Hardware
    Powerpoint
  • Simulation of Ideal and Physical Quantum Computers
    Powerpoint
  • If we would have a quantum computer what can we do with it?
    Powerpoint
  • Quantum computation (and number partitioning)
    Powerpoint