Events at Physics
Events on Thursday, March 13th, 2014
- R. G. Herb Condensed Matter Seminar
- Many body localization: a new frontier for quantum statistical physics
- Time: 10:00 am
- Place: 5310
- Speaker: Rahul Nandkishore, Princeton University
- Abstract: "The existing theory of quantum statistical mechanics describes open systems in contact with large reservoirs. However, experimental advances in the construction and control of isolated quantum systems have highlighted the need for an analogous theory of isolated systems. It has been realized that isolated quantum systems can support behavior which has no analog in open quantum systems. A prominent example is the phenomenon of many body localization.
Many body localization occurs in isolated quantum systems, usually with strong disorder, and is marked by absence of dissipation, absence of thermal equilibration, a strictly zero DC conductivity (even at energy densities corresponding to high temperatures), and a memory of the initial conditions that survives in local observables for arbitrarily long times. Recently, my co-workers and I have demonstrated that many body localization also opens the door to new states of matter which cannot exist in thermal equilibrium, such as topological order at finite energy density, or broken symmetry states below the equilibrium lower critical dimension. In this talk, I review the essential features of the many body localization phenomenon, present our recent work on localization protected order, and provide a survey of open problems. I also present my ongoing work seeking to make contact between the theory and experiments, and discuss potential technological applications of these ideas.“
- Host: Chubukov
- Astronomy Colloquium
- "The secret lives of Galaxy Clusters"
- Time: 3:30 pm - 5:00 pm
- Place: 4421 Sterling Hall
- Speaker: Brian O'shea, Michigan State University
- Abstract: Galaxy clusters have the potential to be highly accurate probes of cosmological parameters. However, they are also very interesting astrophysical objects in their own right! The properties that make clusters irritating to those who wish to use them for cosmology - deviations from sphericity and hydrostatic equilibrium, shocks, mergers, and a variety of baryonic processes - provide a tremendous amount of information about these massive beasts. I will present recent efforts to understand the effects that correctly modeling the properties of gas in cosmological simulations have on the observable properties of clusters, focusing on shocks, AGN heating, and the non- thermal components of the intracluster medium, including cosmic rays and magnetic fields.
- Faculty Candidate Seminar
- Quantum control of interactions between spin and photons in semiconductor quantum dot
- Time: 4:00 pm
- Place: 4274 Chamberlin Hall
- Speaker: Wei-bo Gao, Institute of Quantum Electronics - ETH Zurich
- Abstract: Optically active quantum dot represents a unique quantum system that combines solid state spin qubits with coherent optical transitions. It performs as a natural link between the study of nanoscience, atomic quantum optics and quantum information. Particularly in the frame of quantum information, my talk will focus on the optical manipulation of a quantum dot spin. Based on that, I will report the creation of entanglement between a flying photon and a semiconductor quantum dot spin, acting as a key step towards a quantum network with nodes consisting of semiconductor spin qubits. In the end, I will make a prospect and talk about where we stand in the quantum information application with optically active quantum dot.
- Host: Eriksson/Coppersmith