ELFT HÍRADÓ

[Tamás Kiss <kiss.tamas.magyarorszag AT gmail.com>]

Meghívó

Wigner FK SZFI Kvantuminformatika csoportszeminárium

Ideje: július 20, csütörtök, 13:00
Helye: Wigner FK SZFI 1. épület, hátsó előadóterem

Előadó:
    Thomas Gorin
    Universidad de Guadalajara, Mexico

Quantum processes with non-unitary gates for solving optimization problems


The capacity to solve optimization problems efficiently is fundamental
in life. From the evolution and survival of organisms to the solution of
Travelling Salesman type problems in the flow of goods and services. Though
it is natural to ask, whether quantum algorithms can outperform classical
ones. Traditionally, quantum algorithms are assembled from a few basic quantum
gates and protected from decoherence and errors by quantum error correction.
But one may envisage building algorithms from imperfect (non-unitary) quantum
gates, which may be realizable with current quantum computers.

In this talk, I will discuss a proof of principle that such a strategy might
actually work. Starting from the classical zero-temperature Metropolis
algorithm for the minimum search in an Ising spin system, we replace random
which-path decisions by superpositions of all possible paths. We them show
by numerical simulations that the resulting relaxation process has different
scaling properties than the original classical one. This remains true even
when the decoherence rate is drastically reduced. Finally, we find that the
scaling properties also depend on the phases chosen for the superpositions,
with the result that the relaxation times may be larger or shorter than the
classical one.

Szívesen látunk minden érdeklődőt.

Kiss Tamás