Events Archive

Physics Group Meeting | Pavel Putrov, Member, School of Natural Sciences, IAS | “Link Invariants and Topological Quantum Matter”
Wed, May 10, 2017, 1:45 pm1:45 pm

Gauging of bosonic and fermionic symmetry protected topological (SPT) states with discrete symmetry produces simple yet non-trivial topological quantum field theories (TQFTs). Some of the natural observables in such TQFTs are expectation values of line and surface operators linked in space-time. I would like to discuss what link invariants are…

Next-generation atomic clocks - G. Edward Marti, JILA
Tue, Feb 21, 2017, 1:30 pm1:30 pm

Abstract: The accuracy of atomic clocks has improved a thousandfold over the last 15 years, driven by improvements in ultrastable lasers, quantum control, and our understanding of atomic interactions. The latest generation of optical lattice clocks are accurate enough to measure general relativity's gravitational redshift at the centimeter…

New quantum phases of matter in strongly correlated and spin-orbit-coupled metals - John Harter, Caltech
Mon, Feb 20, 2017, 1:00 pm1:00 pm

Strong interactions between electrons are known to drive metallic systems toward a variety of well-known symmetry-broken phases, including superconducting, electronic liquid crystalline, and charge- and spin-density wave ordered states. In contrast, the electronic instabilities of correlated metals with strong spin-orbit coupling have only…

Physics Group Meeting | Matias Zaldarriaga, Faculty, School of Natural Sciences, IAS | “Discussion of MOND and LCDM”
Wed, Feb 15, 2017, 1:45 pm1:45 pm

I will review the phenomenological successes of MOND on the scale of galaxies. I will discuss its failure on cosmological scales. These large scale problems have been understood for decades, are very robust and their origin can be easily understood.  On the scales of galaxies, rotation curves are well described by the MOND force law without any…

Probing Topological Valley Physics in Bilayer Graphene - Long Ju, Cornell University
Tue, Feb 7, 2017, 1:30 pm1:30 pm

Graphene has been a model solid state system where novel quantum phenomena emerge from the interplay between symmetry, band topology and reduced dimensionality. In particular, AB-stacked bilayer graphene has a unique bandstructure with an electrically tunable bandgap and a valley-dependent Berry phase. These features result in unusual…

Ultracold Fermi Gases: From Strongly Interacting Superfluids to Mott Insulators. - Lawrence Cheuk - MIT
Tue, Jan 31, 2017, 1:30 pm2:30 pm

 

The past decades have seen rapid advances in our capabilities to probe and manipulate atoms. Novel cooling methods have led to quantum degeneracy of large ensembles of atoms. Combined with the ability to tune interactions via Feshbach resonances and energy landscapes via optical potentials, ultracold fermionic atoms have…

Superconducting Quantum Electronics - Eli Levenson-Falk - Berkeley
Fri, Jan 27, 2017, 2:30 pm3:30 pm
Superconducting materials enable the creation of novel electronics with fundamentally non-classical behavior. These quantum circuits can be used as detectors, magnetic field sensors, artificial atoms, and quantum bits, with applications ranging from chemistry to cryptography to studies of basic quantum mechanics. Fully realizing this…
Shining light on topological insulators and Weyl semimetals - Liang Wu, Berkeley
Wed, Jan 25, 2017, 1:30 pmTue, Dec 20, 2016, 2:30 pm
The last decade has witnessed an explosion of research investigating the role of topology in band-structure, as exemplified by the wealth of recent works on topological insulators (TIs) and Weyl semimetals (WSMs). In this talk I hope to convince you that optical probes of solids give unique insight into these topological states of matter. First,…
Shining light on topological insulators and Weyl semimetals - Liang Wu, Berkeley
Wed, Jan 25, 2017, 1:30 pm2:30 pm
The last decade has witnessed an explosion of research investigating the role of topology in band-structure, as exemplified by the wealth of recent works on topological insulators (TIs) and Weyl semimetals (WSMs). In this talk I hope to convince you that optical probes of solids give unique insight into these topological states of matter. First,…
Design and Construction of Oxide Heterostructures with Emergent Properties- Julia Mundy - UC Berkeley
Tue, Jan 24, 2017, 1:30 pm2:30 pm
Materials systems with many strongly interacting degrees of freedom can host some of the most exotic physical ground states known. The subtle interplay of Coulomb interactions, electron-lattice coupling and spin/orbital ordering gives rise to phenomena as diverse as high-temperature superconductivity and topological insulating states as well as…
Synthesizing and probing quantum states of low-entropy atomic systems - Adam Kaufman - Harvard University
Mon, Jan 9, 2017, 1:30 pm2:30 pm
In this talk, I will describe two experimental platforms --- optical tweezer trapping of single atoms and quantum gas microscopy --- and how we have used them to realize experiments with low-entropy systems of neutral atoms. While these platforms share a common goal of creating and microscopically manipulating quantum states of neutral atoms,…
Special Seminar, Anthony Sigillito, Princeton University, "Electric field control of electronic and nuclear spin qubits in silicon"
Fri, Dec 16, 2016, 12:00 pm1:00 pm
Donor electronic and nuclear spins in silicon form two-level systems with coherence times exceeding seconds, making them promising qubits for quantum computing applications. These spins are typically manipulated using microwave magnetic fields. However, magnetic fields are difficult to confine at the nanoscale, which poses problems when moving…
Special Seminar | Monika Scholz, UChicago | "To eat or not to eat: Feeding in noisy conditions"
Wed, Dec 14, 2016, 1:00 pm2:00 pm
Animals generally forage on inhomogeneous landscapes, where nutritional content varies in space and time. Therefore they need to assess the benefit of immediate intake versus waiting for better times. The process of feeding itself incurs an energetic cost in most animals, which poses a cost-benefit question: is the environment nutrient rich…
Special Seminar, Johanna Nagy "Probing Inflation with SPIDER, a Balloon-Borne CMB Polarimeter"
Wed, Dec 14, 2016, 11:00 am12:00 pm
TITLE Probing Inflation with SPIDER, a Balloon-Borne CMB Polarimeter ABSTRACT The generation of a stochastic gravitational wave background is a key prediction of cosmological theories of inflation. At large angular scales, these gravitational waves would imprint a "B-mode" polarization pattern in the Cosmic Microwave Background, providing a…
Special HET Seminar | Mario Martone, Cornell University | “Understanding the Landscape of N=2 Super-conformal Field Theories”
Thu, Dec 8, 2016, 1:45 pm2:45 pm
In this talk I will argue that a systematic classification of 4d N=2 superconformal field theories is possible through a careful analysis of the geometry of their Coulomb branches. I will carefully describe this general framework and then carry out the classification explicitly in the rank-1, that is one complex dimensional Coulomb branch, case…