Probing and Manipulating Ultracold Fermi Superfluids

Simple item page
dc.contributor.advisorPu, Hanen_US
dc.creatorJiang, Leien_US
dc.date.accessioned2013-03-08T00:34:44Zen_US
dc.date.available2013-03-08T00:34:44Zen_US
dc.date.issued2012en_US
dc.description.abstractUltracold Fermi gas is an exciting field benefiting from atomic physics, optical physics and condensed matter physics. It covers many aspects of quantum mechanics. Here I introduce some of my work during my graduate study. We proposed an optical spectroscopic method based on electromagnetically-induced transparency (EIT) as a generic probing tool that provides valuable insights into the nature of Fermi paring in ultracold Fermi gases of two hyperfine states. This technique has the capability of allowing spectroscopic response to be determined in a nearly non-destructive manner and the whole spectrum may be obtained by scanning the probe laser frequency faster than the lifetime of the sample without re-preparing the atomic sample repeatedly. Both quasiparticle picture and pseudogap picture are constructed to facilitate the physical explanation of the pairing signature in the EIT spectra. Motivated by the prospect of realizing a Fermi gas of 40 K atoms with a synthetic non-Abelian gauge field, we investigated theoretically BEC-HCS crossover physics in the presence of a Rashba spin-orbit coupling in a system of two-component Fermi gas with and without a Zeeman field that breaks the population balance. A new bound state (Rashba pair) emerges because of the spin-orbit interaction. We studied the properties of Rashba pairs using a standard pair fluctuation theory. As the two-fold spin degeneracy is lifted by spin-orbit interaction, bound pairs with mixed singlet and triplet pairings (referred to as rashbons) emerge, leading to an anisotropic superfluid. We discussed in detail the experimental signatures for observing the condensation of Rashba pairs by calculating various physical observables which characterize the properties of the system and can be measured in experiment. The role of impurities as experimental probes in the detection of quantum material properties is well appreciated. Here we studied the effect of a single classical impurity in trapped ultracold Fermi superfluids. Although a non-magnetic impurity does not change macroscopic properties of s-wave Fermi superfluids, depending on its shape and strength, a magnetic impurity can induce single or multiple mid-gap bound states. The multiple mid-gap states could coincide with the development of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) phase within the superfluid. As an analog of the Scanning Tunneling Microscope, we proposed a modified radio frequency spectroscopic method to measure the focal density of states which can be employed to detect these states and other quantum phases of cold atoms. A key result of our self consistent Bogoliubov-de Gennes calculations is that a magnetic impurity can controllably induce an FFLO state at currently accessible experimental parameters.en_US
dc.format.extent110 p.en_US
dc.format.mimetypeapplication/pdfen_US
dc.identifier.callnoTHESIS PHYS. 2012 JIANGen_US
dc.identifier.citationJiang, Lei. "Probing and Manipulating Ultracold Fermi Superfluids." (2012) Diss., Rice University. <a href="https://hdl.handle.net/1911/70279">https://hdl.handle.net/1911/70279</a>.en_US
dc.identifier.digitalJiangLen_US
dc.identifier.urihttps://hdl.handle.net/1911/70279en_US
dc.language.isoengen_US
dc.rightsCopyright is held by the author, unless otherwise indicated. Permission to reuse, publish, or reproduce the work beyond the bounds of fair use or other exemptions to copyright law must be obtained from the copyright holder.en_US
dc.subjectPure sciencesen_US
dc.subjectUltracold gaseden_US
dc.subjectDegenerate Fermi gasesen_US
dc.subjectSuperfluidsen_US
dc.subjectBEC-BCS crossoveren_US
dc.subjectLow temperature physicsen_US
dc.subjectCondensed matter physicsen_US
dc.subjectAtomsen_US
dc.subjectSubatomic particlesen_US
dc.titleProbing and Manipulating Ultracold Fermi Superfluidsen_US
dc.typeThesisen_US
dc.type.materialTexten_US
thesis.degree.departmentPhysicsen_US
thesis.degree.disciplineNatural Sciencesen_US
thesis.degree.grantorRice Universityen_US
thesis.degree.levelDoctoralen_US
thesis.degree.nameDoctor of Philosophyen_US
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
JiangL.pdf
Size:
5.64 MB
Format:
Adobe Portable Document Format
Download
Collections
Rice University Theses and Dissertations