Events on Thursday, October 31st, 2024
- R. G. Herb Condensed Matter Seminar
- Optical signatures of interlayer electron coherence in a bilayer semiconductor
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin
- Speaker: Pavel Dolgirev , Harvard University
- Abstract: Emergent strongly-correlated electronic phenomena in atomically-thin transition metal dichalcogenides are an exciting frontier in condensed matter physics, with examples ranging from bilayer superconductivity and electronic Wigner crystals to the ongoing quest for exciton condensation. Here, we experimentally investigate the properties of indirect excitons in naturally-grown MoS2-homobilayer, integrated in a dual-gate device structure allowing independent control of the electron density and out-of-plane electric field. Under conditions when electron tunneling between the layers is negligible, upon electron doping the sample, we observe that the two excitons with opposing dipoles hybridize, displaying unusual behavior distinct from both conventional level crossing and anti-crossing. We show that these observations can be explained by static random coupling between the excitons, which increases with electron density and decreases with temperature. We argue that this phenomenon is indicative of a spatially fluctuating order parameter in the form of interlayer electron coherence, a theoretically predicted many-body state that has yet to be unambiguously established experimentally outside of the quantum Hall regime. Implications of our findings for future experiments and quantum optics applications are discussed.
- Host: Ilya Esterlis
- Astronomy Colloquium
- Building a Multidisciplinary Community: The Impact of Sonification World Chat in Astronomy
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Kate Meredith, Geneva Lake Astrophysics and STEAM
- Abstract: The Sonification World Chat (SWC), initiated in February 2020, addresses the growing need for collaboration and information sharing among diverse sonification projects in astronomy. Central to SWC's mission is the inclusion of blind and low-vision (BLV) individuals, whose insights are crucial for the development of effective sonification tools, interfaces, and algorithms.
Developers without extensive accessibility experience may unintentionally adopt paternalistic approaches, missing critical insights from the BLV community. SWC was established to counteract this by promoting advocacy, project support, and collaboration.
SWC fosters a diverse professional community, including experts in science, accessibility, user-centered design, audio-acoustical engineering, music, education, and the cultural dimensions of sound perception. This diversity ensures that sonification projects can address both technical and human aspects comprehensively.
This session will provide an overview of the multidisciplinary nature of sonification and highlight key projects developed under SWC. Kate will present high-level overviews of initiatives such as Astronify (Space Telescope Science Institute), Star Sound and Vox Magellan (Swinburne University), SonoUno and Sensing the Dynamic Universe (Harvard University), and her work with the Audible Universe Meetings sponsored by the Lorentz Institute at Leiden University, Netherlands.
- Host: Melinda Soares-Furtado