{"686179":{"#nid":"686179","#data":{"type":"event","title":"PhD Defense by Xiaoyong Zhang  ","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ESchool of Physics Thesis Dissertation Defense\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003E\u0026nbsp;\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EXiaoyong Zhang \u0026nbsp;\u003C\/strong\u003E\u003Cbr\u003EAdvisor: Dr.\u0026nbsp;Carlos S\u00e1 de Melo, School of Physics, Georgia Institute of Technology\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EOne-Dimensional Interacting Fermions with Spin-Orbit Coupling: Collective Excitations and Spin-Charge Hybridization\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDate: Friday, November 7, 2025 \u0026nbsp;\u003Cbr\u003ETime:\u0026nbsp; 11:00 a.m. \u0026nbsp;\u0026nbsp;\u0026nbsp;\u0026nbsp;\u003Cbr\u003ELocation: Howey W401\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EZoom link\u003C\/strong\u003E: \u0026nbsp;\u003Ca href=\u0022https:\/\/gatech.zoom.us\/j\/95152479502?pwd=vN0LD1PD6Zavg6qxWlYifU5Ya07pjy.1\u0022\u003Ehttps:\/\/gatech.zoom.us\/j\/95152479502?pwd=vN0LD1PD6Zavg6qxWlYifU5Ya07pjy.1\u003C\/a\u003E\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EMeeting ID: 951 5247 9502\u003C\/p\u003E\u003Cp\u003EPasscode: 191324\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee Members\u003C\/strong\u003E:\u003C\/p\u003E\u003Cp\u003EDr. Martin Mourigal, School of Physics, Georgia Institute of Technology\u003C\/p\u003E\u003Cp\u003EDr. Michael Pustilnik, School of Physics, Georgia Institute of Technology\u003C\/p\u003E\u003Cp\u003EDr. Chandra Raman, School of Physics, Georgia Institute of Technology\u003C\/p\u003E\u003Cp\u003EDr. Luiz Santos, Department of Physics, Emory University\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EAbstract\u003C\/strong\u003E:\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EOne-dimensional fermionic systems exhibit rich collective behavior described by Tomonaga-Luttinger liquid theory, where interactions drive collective excitations into distinct charge and spin density waves that propagate at different velocities, a phenomenon known as the spin-charge separation. A natural question is how these collective modes are modified by additional effects present in those systems, such as spin-orbit coupling. Specifically, does the spin-momentum locking introduced by spin-orbit coupling dramatically influence excitations and fundamentally modify their nature?\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003EThis work aims to address these questions by showing that for SU(2) fermions, short-range interactions produce hybridized spin-charge modes with tunable velocities, while long-range Coulomb interactions give rise to a non-linear plasmon-hybrid mode and an acoustic-hybrid mode. Computation and analysis of the dynamical structure factor tensor provide a direct characterization of the hybridization among collective excitations and establish a connection between theoretical predictions and experimentally accessible observables. Extending to higher-symmetry systems, SU(3) fermions with \u201ccolor-orbit coupling\u201d are studied both with and without interactions. \u0026nbsp;The bosonization formalism is generalized to provide a method for determining the energy dispersion in the long-wavelength limit. This approach is further examined in the non\u2013color-momentum\u2013coupling limit, where a generalized mode separation emerges, consisting of one total-density mode and two degenerate spin-like modes. This work demonstrates that spin-orbit coupling serves as a universal mechanism for hybridizing collective modes in one-dimensional quantum liquids, providing a theoretical basis for exploring correlated quantum dynamics in engineered low-dimensional systems.\u003C\/p\u003E\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003E\u0026nbsp;\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003EOne-Dimensional Interacting Fermions with Spin-Orbit Coupling: Collective Excitations and Spin-Charge Hybridization\u003C\/strong\u003E\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"  One-Dimensional Interacting Fermions with Spin-Orbit Coupling: Collective Excitations and Spin-Charge Hybridization"}],"uid":"27707","created_gmt":"2025-11-04 19:29:34","changed_gmt":"2025-11-04 19:30:11","author":"Tatianna Richardson","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2025-11-07T11:00:00-05:00","event_time_end":"2025-11-07T13:00:00-05:00","event_time_end_last":"2025-11-07T13:00:00-05:00","gmt_time_start":"2025-11-07 16:00:00","gmt_time_end":"2025-11-07 18:00:00","gmt_time_end_last":"2025-11-07 18:00:00","rrule":null,"timezone":"America\/New_York"},"location":"Howey W401","extras":[],"groups":[{"id":"221981","name":"Graduate Studies"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"}],"core_research_areas":[],"news_room_topics":[],"event_categories":[{"id":"1788","name":"Other\/Miscellaneous"}],"invited_audience":[{"id":"78771","name":"Public"}],"affiliations":[],"classification":[],"areas_of_expertise":[],"news_and_recent_appearances":[],"phone":[],"contact":[],"email":[],"slides":[],"orientation":[],"userdata":""}}}