{"691846":{"#nid":"691846","#data":{"type":"event","title":"Ph.D. Dissertation Defense - Shang Jen Su","body":[{"value":"\u003Cp\u003E\u003Cstrong\u003ETitle\u003C\/strong\u003E\u003Cem\u003E:\u0026nbsp; Quantum Ring States, Covert Communication over Bosonic Channels, and Quantum Secure Direct Communication\u003C\/em\u003E\u003C\/p\u003E\u003Cp\u003E\u003Cstrong\u003ECommittee:\u003C\/strong\u003E\u003C\/p\u003E\u003Cp\u003EDr.\u0026nbsp;Matthieu Bloch, ECE, Chair, Advisor\u003C\/p\u003E\u003Cp\u003EDr.\u0026nbsp;John Barry, ECE\u003C\/p\u003E\u003Cp\u003EDr.\u0026nbsp;Viveck Cadambe, ECE\u003C\/p\u003E\u003Cp\u003EDr.\u0026nbsp;Yanbao Zhang, ORNL\u003C\/p\u003E\u003Cp\u003EDr.\u0026nbsp;Robert Clark, Physics\u003C\/p\u003E","summary":"","format":"limited_html"}],"field_subtitle":"","field_summary":[{"value":"\u003Cp\u003EQuantum communication exploits superposition and entanglement to enable secure and efficient information transfer. This dissertation investigates two aspects of quantum communication. First, we introduce quantum ring states, a class of non-Gaussian mixed states generated through phase modulation and transmission over lossy thermal bosonic channels. These states admit tractable achievable-rate expressions that approach the quantum capacity in the low-power regime and improve covert communication performance. Second, we develop the theoretical foundations of Quantum-Memory-Free (QMF) Quantum Secure Direct Communication (QSDC), an alternative to QKD-based secure communication. We establish privacy amplification theorems for coded sequences and characterize information leakage arising from non-ideal keys and retransmissions, enabling practical and resource-efficient QMF-QSDC protocols.\u003C\/p\u003E","format":"limited_html"}],"field_summary_sentence":[{"value":"Quantum Ring States, Covert Communication over Bosonic Channels, and Quantum Secure Direct Communication "}],"uid":"28475","created_gmt":"2026-08-20 21:52:03","changed_gmt":"2026-08-20 21:53:23","author":"Daniela Staiculescu","boilerplate_text":"","field_publication":"","field_article_url":"","field_event_time":{"event_time_start":"2026-08-25T14:00:00-04:00","event_time_end":"2026-08-25T16:00:00-04:00","event_time_end_last":"2026-08-25T16:00:00-04:00","gmt_time_start":"2026-08-25 18:00:00","gmt_time_end":"2026-08-25 20:00:00","gmt_time_end_last":"2026-08-25 20:00:00","rrule":null,"timezone":"America\/New_York"},"location":"Room 423, TSRB","extras":[],"related_links":[{"url":"https:\/\/teams.microsoft.com\/meet\/221101062853515?p=OguZyzuMBLCdu23pb7","title":"Microsoft Teams Link "}],"groups":[{"id":"434381","name":"ECE Ph.D. Dissertation Defenses"}],"categories":[],"keywords":[{"id":"100811","name":"Phd Defense"},{"id":"1808","name":"graduate students"}],"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":""}}}