Events at Physics |
Events on Thursday, April 25th, 2024
- R. G. Herb Condensed Matter Seminar
- Rydberg physics: From Ultralong-Range Molecules to Quantum Simulation and Quantum Optimization
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin
- Speaker: Peter Schmelcher, U Hamburg
- Abstract: A review on the most recent activities in Rydberg physics at the center for optical quantum technologies will be provided. I start out with addressing the exotic properties of ultralong-range Rydberg molecules (ULRM). ULRM possess extreme bond lengths of the order of several micron and huge dipole moments. Their potential energy curves mimic the highly oscillatory structure of the Rydberg wave function thereby offering new possibilities for engineering molecular properties on vastly different time and length scales. Trilobite and butterfly states can easily be controlled by weak external electric or magnetic fields. I demonstrate that synthetic dimensions based on quantum numbers can be used to design conical intersections and consequently non-adiabatic interaction effects in the spectra of ULRMs. Ultrafast decay processes are a consequence of these intersections. Quenches of external fields then lead to a rich rovibrational quantum dynamics of ULRM. The second part of this talk focuses on quantum simulation and quantum optimization. I provide evidence for novel quantum phases of strongly interacting many-body Rydberg setups, specifically the so-called bond order density wave is unraveled and the extended control of Luttinger liquid phases is presented. On the quantum optimization side I describe how a local detuning approach can enhance the tweezer array-based control of the famous graph theoretical MIS and Max-Cut problems. The traditional order $\propto N^2$ approach is here replaced by a linear system size scaling approach. Finally, I will make a short excursion into our recent work on single atom implementation of integer linear programming. Here, a single Rydberg atom will be used to encode linear and even nonlinear integer problems which are known to be difficult to solve in a classical manner.
- Host: Mark Saffman
- Preliminary Exam
- Progress towards cooling and imaging on an alkali atom forbidden transition
- Time: 11:00 am - 1:00 pm
- Place: Sterling Hall B343
- Speaker: Jacob Scott, Physics PhD Graduate Student
- Abstract: I present progress towards atomic manipulation on the 6S1/2 - 5D5/2 forbidden transition in Cs. I discuss a few intriguing features of this transition, including a very high pump-depump ratio, very low Doppler temperature, and an intermediate state that allows for background free imaging. I also discuss development of the experimental apparatus and preliminary results of the experiment.
- Host: Mark Saffman
- NPAC (Nuclear/Particle/Astro/Cosmo) Forum
- NOvA Cross-section Measurement of Muon Antineutrino Charge Current Inclusive Interactions
- Time: 3:30 pm - 4:30 pm
- Place: 5280 Chamberlin Hall
- Speaker: Prabhjot Singh, Queen Mary University of London
- Abstract: Neutrino-nucleus interactions are one of the major systematics in neutrino oscillation experiments. In this high-precision era of neutrino oscillation measurements, the neutrino oscillation experiments need to have a good understanding of neutrino-nucleus interactions to reduce uncertainties in the oscillation measurements. NOvA is a long-baseline accelerator-based internationally-collaborated neutrino experiment based in the USA. NOvA uses an intense neutrino beam produced at Fermilab’s accelerator complex to make physics measurements of neutrino oscillations, neutrino cross sections, and other exotic and beyond the Standard Model neutrino analyses. For its physics goals, NOvA uses two functionally identical detectors. The Near Detector (ND) is situated at Fermilab, 1 km from the neutrino target and the Far Detector (FD) is located at Ash River, MN, 810 km from the neutrino source. The ND sees a high intensity of the neutrino beam due to its proximity to the neutrino target. This gives us a unique opportunity for high-precision neutrino cross-section measurements. In this seminar, we will talk about the motivations for doing neutrino cross-section measurements. We will also discuss different aspects of the NOvA experiment, and detectors. Finally, we present our latest muon antineutrino charge current inclusive cross-section measurement results in the NOvA ND. The new measurement is a triple differential cross section in antimuon kinematic phase-space and in the total energy of all observable final state hadrons, also known as the available energy. We also compare our data results to various neutrino generator predictions, for example, comparisons to GENIE, NuWro, NEUT, and GiBUU neutrino generators are presented.
- Host: Brian Rebel
- Astronomy Colloquium
- Goodbye to “Chi-by-Eye” : Results from a Bayesian Analysis of Photometric Binaries in Open Clusters
- Time: 3:30 pm - 4:30 pm
- Place: 4421 Sterling Hall
- Speaker: Aaron M Geller, Northwestern University
- Abstract: Binary and higher-order multiple stars are ubiquitous, and their evolution can be dramatically influenced by their environment. Binaries in the field evolve essentially in isolation, while those within star clusters may experience frequent close stellar encounters that can significantly modify, and even disrupt, their orbits. Most stars like our Sun are believed to be born in star clusters, many of which dissolve to populate the field. Therefore, our interpretation of the observed binary populations in star clusters and the field (and even to some extent our understanding of star formation), relies on how a population of stars evolves through this more dynamically active stage in a star cluster. In this talk, I will provide an overview of the work my team and collaborators are pursuing to identify and analyze photometric binaries in galactic open clusters, in order to test predictions of star cluster models and learn about the dynamical state of our galactic open cluster population.
- Host: Ke Zhang