5 research outputs found
Realistic Interpretation of Quantum Mechanics and Encounter-Delayed-Choice Experiment
A realistic interpretation(REIN) of wave function in quantum mechanics is
briefly presented in this work.
In REIN, the wave function of a microscopic object is just its real existence
rather than a mere mathematical description. Quantum object can exist in
disjoint regions of space which just as the wave function distributes, travels
at a finite speed, and collapses instantly upon a measurement. The single
photon interference in a Mach-Zehnder interferometer is analyzed using REIN. In
particular, we proposed and experimentally implemented a generalized
delayed-choice experiment, the encounter-delayed-choice(EDC) experiment, in
which the second beam splitter is inserted at the encounter of the two
sub-waves from the two arms. In the EDC experiment, the front parts of wave
functions before the beam splitter insertion do not interfere and show the
particle nature, and the back parts of the wave functions will interfere and
show a wave nature. The predicted phenomenon is clearly demonstrated in the
experiment, and supports the REIN idea.Comment: 7 pages 4 figure
Optimizing a Polynomial Function on a Quantum Simulator
Gradient descent method, as one of the major methods in numerical
optimization, is the key ingredient in many machine learning algorithms. As one
of the most fundamental way to solve the optimization problems, it promises the
function value to move along the direction of steepest descent. For the vast
resource consumption when dealing with high-dimensional problems, a quantum
version of this iterative optimization algorithm has been proposed
recently[arXiv:1612.01789]. Here, we develop this protocol and implement it on
a quantum simulator with limited resource. Moreover, a prototypical experiment
was shown with a 4-qubit Nuclear Magnetic Resonance quantum processor,
demonstrating a optimization process of polynomial function iteratively. In
each iteration, we achieved an average fidelity of 94\% compared with
theoretical calculation via full-state tomography. In particular, the iterative
point gradually converged to the local minimum. We apply our method to
multidimensional scaling problem, further showing the potentially capability to
yields an exponentially improvement compared with classical counterparts. With
the onrushing tendency of quantum information, our work could provide a
subroutine for the application of future practical quantum computers.Comment: 6+4 pages, 8 figure