Diffraction of a Released Bose-Einstein Condensate by a Pulsed Standing Light Wave

1999 ◽  
Vol 83 (2) ◽  
pp. 284-287 ◽  
Author(s):  
Yu. B. Ovchinnikov ◽  
J. H. Müller ◽  
M. R. Doery ◽  
E. J. D. Vredenbregt ◽  
K. Helmerson ◽  
...  
2010 ◽  
Vol 20 (02) ◽  
pp. 255-261 ◽  
Author(s):  
I. DANA ◽  
V. B. ROITBERG ◽  
V. RAMAREDDY ◽  
I. TALUKDAR ◽  
G. S. SUMMY

A theory of quantum ratchets for a particle periodically kicked by a general periodic potential under quantum-resonance conditions is developed for arbitrary values of the conserved quasimomentum β. A special case of this theory is experimentally realized using a Bose–Einstein condensate (BEC) exposed to a pulsed standing light wave. While this case corresponds to completely symmetric potential and initial wave-packet, a purely quantum ratchet effect still arises from the generic noncoincidence of the symmetry centers of these two entities. The experimental results agree well with the theory after taking properly into account the finite quasimomentum width of the BEC. This width causes a suppression of the ratchet acceleration occurring for "resonant" β, so that the mean momentum saturates to a finite ratchet velocity, strongly pronounced relative to that for nonresonant β.


2021 ◽  
Vol 126 (3) ◽  
Author(s):  
T. Dieterle ◽  
M. Berngruber ◽  
C. Hölzl ◽  
R. Löw ◽  
K. Jachymski ◽  
...  

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tobias Kroker ◽  
Mario Großmann ◽  
Klaus Sengstock ◽  
Markus Drescher ◽  
Philipp Wessels-Staarmann ◽  
...  

AbstractPlasma dynamics critically depends on density and temperature, thus well-controlled experimental realizations are essential benchmarks for theoretical models. The formation of an ultracold plasma can be triggered by ionizing a tunable number of atoms in a micrometer-sized volume of a 87Rb Bose-Einstein condensate (BEC) by a single femtosecond laser pulse. The large density combined with the low temperature of the BEC give rise to an initially strongly coupled plasma in a so far unexplored regime bridging ultracold neutral plasma and ionized nanoclusters. Here, we report on ultrafast cooling of electrons, trapped on orbital trajectories in the long-range Coulomb potential of the dense ionic core, with a cooling rate of 400 K ps−1. Furthermore, our experimental setup grants direct access to the electron temperature that relaxes from 5250 K to below 10 K in less than 500 ns.


2021 ◽  
Vol 240 (1) ◽  
pp. 383-417
Author(s):  
Nikolai Leopold ◽  
David Mitrouskas ◽  
Robert Seiringer

AbstractWe consider the Fröhlich Hamiltonian in a mean-field limit where many bosonic particles weakly couple to the quantized phonon field. For large particle numbers and a suitably small coupling, we show that the dynamics of the system is approximately described by the Landau–Pekar equations. These describe a Bose–Einstein condensate interacting with a classical polarization field, whose dynamics is effected by the condensate, i.e., the back-reaction of the phonons that are created by the particles during the time evolution is of leading order.


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