BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Memento EPFL// BEGIN:VEVENT SUMMARY:Junior Quantum Seminar - Hana K. Warner & Matthew Yeh DTSTART:20250512T153000 DTEND:20250512T173000 DTSTAMP:20260503T083113Z UID:389cacc69842d59465be320ff6a16e2ea617adbc7e3c80cd4465890d CATEGORIES:Conferences - Seminars DESCRIPTION:Hana K. Warner\, Matthew Yeh\nPlease join us for the Junior Quantum Seminar with Hana K. Warner from Harvard University who will g ive the talk "Optical Interconnects for Microwave Frequency Superconductin g Qubits" and Matthew Yeh from Harvard University who will give the talk "Electro-optics does not exist without electronics" on Monday May 12th fr om 3:30pm to 5:30pm in room BS 260.\n\nPLEASE NOTE: The Junior Quantum Ser ies are for gathering  the junior quantum community of master's studen ts\, PhDs and post-docs at EPFL\, to create a non-judgmental space were sc ientific ideas can be shared between peers. This event is not for Professo rs or senior researchers. \n\nABSTRACT:\n\n "Optical Interconnects for Mi crowave Frequency Superconducting Qubits": Superconducting (SC) microwave qubits are a promising platform for realizing a valuable computational res ource in a quantum cloud\, where superconducting processors are linked via a network to realize the large number of qubits required for practical qu antum computing. However\, creating this link is challenging due to signal attenuation and noise sensitivity characteristic of their operating frequ ency. Optical photons\, on the other hand\, are ideal long-distance inform ation carriers because they exhibit low propagation losses in modern fiber optic networks\, are insensitive to thermal noise at room temperature\, a nd modern single photon detectors enable efficient information transfer: f urthermore\, the high bandwidth and low thermal load of optical fibers mea ns radio-over-fiber techniques can be leveraged to enable dense\, low temp erature interfaces for qubit control and readout. Here\, I will discuss wo rk on using the electro-optic (EO) effect in thin-film lithium niobate (TF LN) to mediate a direct conversion process between microwave and optical r adiation. This is ideal for enabling high repetition rates and minimizing the generation of excess noise. By coupling optical resonators in TFLN to SC microwave resonators we enhance the conversion process by orders of mag nitude\, allowing us to overcome the large energy gap between the two regi mes. I will discuss work on developing efficient\, low-noise EO transducer s used to coherently drive SC processors\, as well as progress towards usi ng the devices to create long-haul quantum links between superconducting q ubit nodes.  \n Electro-optics does not exist without electronics": Thin -film lithium niobate has had great success revolutionizing commercial mar kets for modulators\, as well as being a promising candidate material plat form for emerging applications such as quantum photonics. Nearly all appli cations\, from the single modulator level to increasingly complex integrat ed photonic circuits require a bias point. To this end\, the linear electr o-optic (Pockels) effect seems a natural fit—it is efficient\, low-power \, and cryo-compatible. However\, in practice many complex device phenomen a emerge during dc biasing for extended periods of time\, complicating the utility of this nominally simple tuning knob. In this talk I will discuss the zoo of phenomena that can be observed in this low-frequency regime\, in particular characteristic sources of drift and instability at various d evice interfaces. By simply changing perspectives to a defect-oriented int erpretation more characteristic of well-established semiconductor engineer ing\, we can gain fundamental insights and new approaches into the microsc opic origins and possible mitigation techniques for these nonidealities. F inally\, I will conclude with some remarks on possible fundamental limitat ions of electro-optic approaches to phase shifting. \n\nBIO:\n\n\n Hana W arner is a Ph.D. candidate in Applied Physics at Harvard University\, work ing with Prof. Marko Lončar as an NSF Graduate Research Fellow. Her curre nt research focuses on developing hardware for quantum and classical trans duction between microwave and optical frequencies using integrated photoni cs and electro-optics. Previously\, she received bachelor’s degrees in p hysics and mathematics at William & Mary where she worked on topics includ ing atomic gradiometry and orbital angular momentum transfer using nonline ar interactions in rubidium vapor.\n  Matthew Yeh is a PhD candidate in Applied Physics at Harvard University\, co-advised by Marko Loncar and Eve lyn Hu. His current research is focused on materials engineering of the th in-film lithium niobate quantum photonic platform. Previously\, he receive d a bachelor's degree in Electrical Engineering and Computer Science at th e University of California\, Berkeley\, where he worked on various topics in optoelectronics and exciton physics of 2D materials. \n LOCATION:BS 260 https://plan.epfl.ch/?room==BS%20260 STATUS:CONFIRMED END:VEVENT END:VCALENDAR