JQI Seminar

Abstract: While it can be useful in some cases to abstract away all but 2 levels of the atoms used for quantum computing, it should not be forgotten that these qubit hosts often have many levels capable of participating in processing tasks.  These include long-lived states within hyperfine, Zeeman, and electronic-state structure in atoms, but extend to rotational, vibrational, and more exotic level landscapes if one considers molecules instead of just atoms.  Given the effectively atom-limited regime in which many (possibly all) atomic processors currently operate,

Abstract: The SpooQy-1 project designed, built and operated a source of polarisation entangled photon-pairs onboard a CubeSat for over 600 days. From the lessons learned in the SpooQy-1 mission, the Singapore-based team is working towards performing entanglement distribution from a small satellite to ground receivers. In this talk, I will share observations about the performance of the satellite, the entangled photon source, and the single photon detectors in orbit. These data has been used to validate some very useful models for predicting the effect of radiation on components.

Abstract: Why do chaotic quantum many-body systems thermalize internally? The eigenstate thermalization hypothesis (ETH) explains why if the Hamiltonian lacks degeneracies. If the Hamiltonian conserves one quantity ("charge"), the ETH implies thermalization within an eigenspace of the charge—in a microcanonical subspace. However, quantum systems can have charges that fail to commute with each other and so share no eigenbasis; microcanonical subspaces may not exist. Worse, the Hamiltonian will have degeneracies, so the ETH need not imply thermalization.

Abstract: This talk presents recent progress in photonic integrated circuits and solid-state artificial atoms for processing classical and quantum information in deep learning neural networks architectures. These developments can lead to faster and more energy-efficient computing architectures that solve problems with complexities beyond today’s systems.
Location: ATL 2400

Abstract: The dimensionality of a physical system strongly influences its classical and quantum behavior, be it for Ising phase transitions, or the recurrence properties of random walks, or for Anderson localization. Specifically for topological phenomena, richer topological and emergent phases can be expected in higher dimensions. However, experimentally realizing such high-dimensional systems is challenging in real space because it requires complicated spatial structures.

Abstract: The discovery of moiré materials has enabled the studies of condensed matter phenomena in a simpler and more controllable fashion. To a good approximation, the system can be regarded as a lattice of tunable artificial atoms, bridging the gap between real solid-state materials and cold atom quantum simulators. In this talk, I will use an archetypal semiconductor moiré material, angle-aligned MoTe 2 /WSe 2 bilayers, to illustrate how a rich set of condensed matter phenomena can be “simulated” in a single material by simply adjusting the gate voltages in a field-effect device.

Abstract: Research in quantum computing has offered many new physical insights and a potential to exponentially increase the computational power that can be harnessed to solve important problems in science and technology. The largest fundamental barrier to building a scalable quantum computer is errors caused by decoherence. Topological quantum computing overcomes this barrier by exploiting topological materials which, by their nature, limit errors.

Abstract TBA
JQI Seminars are held on Mondays during Fall and Spring semesters at 11:00 a.m. Eastern Time in Room 2400 of the Atlantic Building. University of Maryland affiliates may participate using Zoom. The seminars are also livestreamed on the JQI YouTube channel (https://www.youtube.com/user/JQInews), which supports audience participation in the chat interface.

Abstract: Quantum computing with neutral atoms has progressed rapidly in recent years, combining large system sizes, flexible and dynamic connectivity, and quickly improving gate fidelities. The pioneering work in this field has been implemented using alkali atoms, primarily rubidium and cesium. However, divalent, alkaline-earth-like atoms such as ytterbium offer significant technical advantages.

Abstract TBA
JQI Seminars are held on Mondays during Fall and Spring semesters at 11:00 a.m. Eastern Time in Room 2400 of the Atlantic Building. University of Maryland affiliates may participate using Zoom. The seminars are also livestreamed on the JQI YouTube channel (https://www.youtube.com/user/JQInews), which supports audience participation in the chat interface.