2011 Annual Meeting of the Four Corners Section of the APS
Volume 56, Number 11
Friday–Saturday, October 21–22, 2011;
Tuscon, Arizona
Session L1: Plenary Session III
9:55 AM–11:07 AM,
Saturday, October 22, 2011
UA Student Union
Room: South Ballroom
Chair: James Chisholm, South Utah University
Abstract ID: BAPS.2011.4CF.L1.2
Abstract: L1.00002 : Quantum metrology -- optical atomic clocks and many-body physics.
10:31 AM–11:07 AM
Preview Abstract
Abstract
Author:
Jun Ye
(JILA, NIST and University of Colorado)
Optical clocks based on atoms confined in optical lattices
provide a unique
opportunity for precise study and measurement of quantum many-
body systems.
The state-of-the-art optical lattice clock has reached an overall
fractional
frequency uncertainty of 1 $\times $ 10$^{-16}$ [1]. One dominant
contribution to this uncertainty is clock frequency shift arising
from
atomic collisions. Collisions between initially identical
fermionic Sr atoms
can occur when they are subject to slightly inhomogeneous optical
excitations during the clock operation [2]. We have recently
implemented a
seemingly paradoxical solution to the collisionshift problem:
with a strong
atomic confinement in one-dimensional tube-shaped optical traps,
we
dramatically increase the atomic interactions. Instead of a
naively expected
increase of collisional frequency shifts, these shifts are
increasingly
suppressed [3]. The large atomic interaction strength creates an
effective
energy gap in the system such that inhomogeneous excitations can
no longer
drive fermions into a pseudo-spin antisymmetric state, and hence
their
collisions and the corresponding frequency shifts are suppressed.
We
demonstrate the effectiveness of this approach by reducing the
density-related frequency shift to the level of 10$^{-17}$,
representing
more than a factor of ten reduction from the previous record [1,
2]. In
addition, we have observed well-resolved interaction sidebands
separated
from the main peak of the clock transition, giving a direct
evidence for the
removal of the interaction energy from the clock carrier
transition. Control
of atomic interactions at the level of 1 $\times $ 10$^{-17 }$is
a testimony
to our understanding of a quantum many-body system and it removes
an
important obstacle for building an optical atomic clock based on
such
systems with high accuracy.
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[1] A. D. Ludlow \textit{et al., }Science \textbf{319}, 1805
(2008).
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[2] G. K. Campbell \textit{et al., }Science \textbf{324}, 360
(2009).
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[3] M. D. Swallows \textit{et al}., Science \textbf{331}, 1043
(2011).
To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2011.4CF.L1.2