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Wolfgang Ketterle. Li, Junru,Ph. D.Massachusetts Institute of Technology. Massachusetts Institute of Technology. Department of Physics. Massachusetts Institute of Technology. Department of Physics 2020-01-08T19:31:23Z 2020-01-08T19:31:23Z 2019 2019 https://hdl.handle.net/1721.1/123348 1132797177 This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections. Thesis: Ph. D., Massachusetts Institute of Technology, Department of Physics, 2019 Cataloged from student-submitted PDF version of thesis. Includes bibliographical references (pages 207-214). Ultracold quantum gases provide a clean, isolated, and controllable platform for simulating and characterizing complex physical phenomena. In this thesis, I present several experiments on realizing one-dimensional spin-orbit coupling in ultracold 23Na gases and the creation of a new form of matter with supersolid properties using interacting spin-orbit coupled Bose-Einstein condensates. The first part describes the realization of spin-orbit coupling in optical superlattices which consist of stack of pancakes of imbalanced double-wells. The orbital levels, individual pancakes, in an superlattice potential are used as pseudospin states. Spinorbit coupling was induced by two-photon Raman transition between the pseudospin states, and was experimentally characterized by the spin-dependent momentum structure from this dressing. The realization suppresses heating due to spontaneous emission. The system is highly miscible, allowing the study of novel phases in interacting spin-orbit coupled systems. Next, spin-orbit coupling was demonstrated by synchronizing a fast periodically modulating magnetic force with the Radio-Frequency (RF) pulses. The modulation effectively dressed the RF photons with tunable momentum. The consequent Doppler shifts for RF transitions were observed as velocity-selective spin flips. The scheme is equivalent to Floquet engineered one-dimensional spin-orbit coupling. Finally, I report experiments on creating a new form of matter, a supersolid, in ultracold quantum gases. An interacting spin-orbit coupled Bose-Einstein condensate in the stripe phase spontaneously breaks two continuous symmetries : the U(1) symmetry, observed as sharp interference peaks in momentum space, and the continuous translational symmetry, observed as a spontaneously formed density modulation. The density modulation is measured and characterized with Bragg scattering. A system spontaneously breaking these two symmetries is a crystal and a superfluid simultaneously, and is considered as a supersolid. by Junru Li. Ph.D. Ph.D. Massachusetts Institute of Technology, Department of Physics 214 pages eng Massachusetts Institute of Technology MIT theses are protected by copyright. They may be viewed, downloaded, or printed from this source but further reproduction or distribution in any format is prohibited without written permission. http://dspace.mit.edu/handle/1721.1/7582 Physics. Spin-orbit coupling and supersolidity in ultracold quantum gases Thesis application/pdf 2020-01-08T19:31:21Z Publication Doctoral Phys unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="fd63d89c-401d-4b41-adf0-bbf8a5cf4c20"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Spin-orbit coupling and supersolidity in ultracold quantum gases</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2019</PublicationDate> <Authors> <Author> <DisplayName>Li, Junru,Ph. D.Massachusetts Institute of Technology.</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Physics.</Keyword> <Abstract>Ultracold quantum gases provide a clean, isolated, and controllable platform for simulating and characterizing complex physical phenomena. In this thesis, I present several experiments on realizing one-dimensional spin-orbit coupling in ultracold 23Na gases and the creation of a new form of matter with supersolid properties using interacting spin-orbit coupled Bose-Einstein condensates. The first part describes the realization of spin-orbit coupling in optical superlattices which consist of stack of pancakes of imbalanced double-wells. The orbital levels, individual pancakes, in an superlattice potential are used as pseudospin states. Spinorbit coupling was induced by two-photon Raman transition between the pseudospin states, and was experimentally characterized by the spin-dependent momentum structure from this dressing. The realization suppresses heating due to spontaneous emission.</Abstract> <Abstract>The system is highly miscible, allowing the study of novel phases in interacting spin-orbit coupled systems. Next, spin-orbit coupling was demonstrated by synchronizing a fast periodically modulating magnetic force with the Radio-Frequency (RF) pulses. The modulation effectively dressed the RF photons with tunable momentum. The consequent Doppler shifts for RF transitions were observed as velocity-selective spin flips. The scheme is equivalent to Floquet engineered one-dimensional spin-orbit coupling. Finally, I report experiments on creating a new form of matter, a supersolid, in ultracold quantum gases. An interacting spin-orbit coupled Bose-Einstein condensate in the stripe phase spontaneously breaks two continuous symmetries : the U(1) symmetry, observed as sharp interference peaks in momentum space, and the continuous translational symmetry, observed as a spontaneously formed density modulation. The density modulation is measured and characterized with Bragg scattering.</Abstract> <Abstract>A system spontaneously breaking these two symmetries is a crystal and a superfluid simultaneously, and is considered as a supersolid.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>