Squeezing collective atomic spins with an optical resonator
Name
773288090-MIT.pdf
Description
Full printable version
Size
26.42 MB
Format
Adobe PDF
Checksum (MD5)
9ef63d24961be98e25fe9229a8858699
Author(s)
Leroux, Ian Daniel
Advisor(s)
Vladan Vuletić.
Date Issued
2011
Publisher
Massachusetts Institute of Technology
Abstract
This thesis describes two methods of overcoming the standard quantum limit of signal-to-noise ratio in atomic precision measurements. In both methods, the interaction between an ultracold atomic ensemble and an optical resonator serves to entangle the atoms and deform the uncertainty distribution of the collective hyperfine spin so that it is narrower in some coordinate than would be possible if the atoms were uncorrelated. The first method uses the dispersive shift of the optical resonator's frequency by the atomic index of refraction to perform a quantum non-demolition measurement of the collective spin, projecting it into a squeezed state conditioned on the measurement outcome. The second method exploits the collective coupling of the atoms to the light field in the resonator to generate an effective interaction that entangles the atoms deterministically. Both methods are demonstrated experimentally, achieving metrologically relevant squeezing of 1.5(5) dB and 4.6(6) dB respectively, and simple analytical models, including the effects of scattering into free space, show that much greater squeezing is realistically achievable. To demonstrate the potential usefulness of such squeezing, a proof-of-principle atomic clock whose Allan variance decreases 2.8(3) three times faster than the standard quantum limit is also presented, together with a discussion of the conditions under which squeezing improves its performance.
Description
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2011.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 128-133).
Subjects
Physics.
MIT Department
Massachusetts Institute of Technology. Department of Physics
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