14 research outputs found
Phase Space Tomography of Matter-Wave Diffraction in the Talbot Regime
We report on the theoretical investigation of Wigner distribution function
(WDF) reconstruction of the motional quantum state of large molecules in de
Broglie interference. De Broglie interference of fullerenes and as the like
already proves the wavelike behaviour of these heavy particles, while we aim to
extract more quantitative information about the superposition quantum state in
motion. We simulate the reconstruction of the WDF numerically based on an
analytic probability distribution and investigate its properties by variation
of parameters, which are relevant for the experiment. Even though the WDF
described in the near-field experiment cannot be reconstructed completely, we
observe negativity even in the partially reconstructed WDF. We further consider
incoherent factors to simulate the experimental situation such as a finite
number of slits, collimation, and particle-slit van der Waals interaction. From
this we find experimental conditions to reconstruct the WDF from Talbot
interference fringes in molecule Talbot-Lau interferometry.Comment: 16 pages, 9 figures, accepted at New Journal of Physic
Tailoring discrete quantum walk dynamics via extended initial conditions: Towards homogeneous probability distributions
We study the evolution of initially extended distributions in the coined
quantum walk on the line by analyzing the dispersion relation of the process
and its associated wave equations. This allows us, in particular, to devise an
initially extended condition leading to a uniform probability distribution
whose width increases linearly with time, with increasing homogeneity.Comment: 4 pages, 2 figure
The particle in the box: Intermode traces in the propagator
Characteristic structures such as canals and ridges-intermode traces-emerge in the spacetime representation of the probability distribution of a particle in a one-dimensional box. We show that the corresponding propagator already contains these structures. We relate their visibility to the factorization property of the initial wave packet
Quantum carpet interferometry for trapped atomic Bose-Einstein condensates
We propose an ``interferometric'' scheme for Bose-Einstein condensates using
near-field diffraction. The scheme is based on the phenomenon of intermode
traces or quantum carpets; we show how it may be used in the detection of weak
forces.Comment: 4 figures. Submitted to Phys. Rev.
Quantum carpets woven by Wigner functions
The dynamics of many different quantum systems is characterized by a regular net of minima and maxima of probability stretching out in a spacetime representation. We offer an explanation to this phenomenon in terms of the Wigner function. This approach illustrates very clearly the crucial role played by interference
Quantum carpets and Wigner functions
A particle confined to an infinitely deep potential well is the ideal toy model for studying the origin of the regular patterns appearing for many physical systems in the spacetime representation of the probability density. The Wigner function is a useful tool to bring out the role of interference in the formation of these so-called "quantum carpets"
The particle in the box: Intermode traces in the propagator
No abstract available for this articl