Speaker
Prof.
Philipp Treutlein
(University of Basel, Switzerland)
Description
Abstract: In optomechanics, laser light is used for cooling
and control of the vibrations of micromechanical oscillators,
with many similarities to the cooling and trapping of atoms.
Laser light can also be used to couple the motion of
ultracold atoms in a trap to the vibrations of a mechanical
oscillator. In the resulting hybrid system the atoms can be
used for sympathetic cooling of the oscillator, creating
atom-oscillator entanglement, and controlling the oscillator
on the single-phonon level. We have realized a hybrid
mechanical system in which ultracold atoms and a
micromechanical membrane are coupled by radiation
pressure forces. The atoms are trapped in an optical lattice,
formed by retro-reflection of a laser beam from an optical
cavity that contains the membrane as mechanical element.
When we laser cool the atoms, we observe that
the membrane is sympathetically cooled from ambient to
millikelvin temperatures through its interaction with the
atoms. Sympathetic cooling with ultracold atoms or ions has
previously been used to cool other microscopic systems
such as atoms of a different species or molecular ions up to
the size of proteins. Here we use it to efficiently cool the
fundamental vibrational mode of a macroscopic solid-state
system, whose mass exceeds that of the atomic ensemble
by ten orders of magnitude. Our hybrid system operates in
a regime of large atom-membrane cooperativity. With
realistic improvements it enables ground-state cooling and
quantum control of low-frequency oscillators such as
membranes or levitated nanoparticles, in a regime where
purely optomechanical techniques cannot reach the ground
state.
References:
[1] A. Jöckel, A. Faber, T. Kampschulte, M. Korppi, M. T.
Rakher, and P. Treutlein, "Sympathetic cooling of a
membrane oscillator in a hybrid mechanical-atomic
system", submitted (2014). [2] B. Vogell, K. Stannigel, P.
Zoller, K. Hammerer, M. T. Rakher, M. Korppi, A. Jöckel, and
P. Treutlein, "Cavity-enhanced long-distance coupling of an
atomic ensemble to a micromechanical membrane", Phys.
Rev. A 87, 023816 (2013).
[3] P. Treutlein, C. Genes, K. Hammerer, M. Poggio, and P.
Rabl, "Hybrid Mechanical Systems", in: "Cavity
Optomechanics", ed. by M. Aspelmeyer, T. Kippenberg, F.
Marquardt (Springer). preprint arXiv:1210.4151 (2012).
[4] S. Camerer, M. Korppi, A. Jöckel, D. Hunger, T. W.
Hänsch, and P. Treutlein, "Realization of an optomechanical
interface between ultracold atoms and a membrane", Phys.
Rev. Lett. 107, 223001 (2011).