## Donald R. Hamilton Colloquium Series

4:00 p.m., Thursday, February 16, 2017

**"Invitation to Random Tensors"
**

**Razvan Gurau**, Centre de Physique Théorique (CPHT), École Polytechnique, France

Random matrices are ubiquitous in modern theoretical physics and provide insights on a wealth of phenomena, from the spectra of heavy nuclei to the theory of strong interactions or random two dimensional surfaces.

The backbone of all the analytical results in matrix models is their 1/N expansion (where N is the size of the matrix). Despite early attempts in the '90s, the generalization of this 1/N expansion to higher dimensional random tensor models has proven very challenging. This changed with the discovery of the 1/N expansion (originally for colored and subsequently for arbitrary invariant) tensor models in 2010. In this talk I will present a short introduction to the modern theory of random tensors and its connections to random higher dimensional geometry.

Host: **Igor Klebanov**, Department of Physics, Princeton University

4:00 p.m., Thursday, February 23, 2017

**“****Non-local phenomena in Quantum Mechanics****"**

**Yakir Aharonov,** Chapman University, and Professor Emeritus, Tel Aviv University

I discuss in my talk a reformulation of quantum mechanics in which each quantum system at any time is described by two Hilbert space vectors rather than one. One of the vectors propagates from a past boundary condition towards the present and the other propagates back to the present from a future boundary condition. I will show that this reformulation uncovers a host of fascinating new phenomena, some of which will be described in detail within this talk. Finally, I will show that this new reformulation suggests a novel solution to the notorious problem of the Quantum Measurement.

**Paul Steinhardt**, Princeton Center for Theoretical Physics, Princeton University

4:00 p.m., Thursday, March 2, 2017

**"Neutrino physics from the polarized microwave background"
Jo Dunkley,** Professor of Physics and Astrophysical Sciences, Princeton University

**Lyman Page**, Chair, Department of Physics, Princeton University

4:00 p.m., Thursday, March 9, 2017

**“ Building quantum matter from light: from topological photonics to polariton blockade”**

**Jonathan Simon**, University of Chicago

I will present our recent work building matter from light, beginning with a realization of Landau levels for optical photons in a non-planar (twisted) optical resonator and studying the impact of placing these photons in curved space. I will then discuss our recent success in mediating strong interactions between intra-cavity photons using Rydberg electromagnetically induced transparency. Combining these ideas will enable us to explore strongly correlated topological matter made of light. Time permitting, I will describe a parallel effort to build correlated matter from microwave photons, where circuit QED tools developed for quantum computing are harnessed to mediate interactions between photons. In this work, we are developing tools to stabilize incompressible matter by harnessing engineered dissipation. In summation, we explore photonic materials as a unique alternative to ultracold atoms in optical lattices and electrons in ionic lattices for exploring topological or quantum condensed matter.

**Barry Bradlyn**, Princeton Center for Theoretical Science, Princeton University

Thursday, March 16, 2017

There will not be a colloquium event this week (APS March meeting in New Orleans).

4:00 p.m., Thursday, March 30, 2017

**"Heavy flavor spectroscopy at LHCb"**

**Tomasz Skwarnicki**, Syracuse University

Hadrons with heavy quarks play a special role in studies of structures created by strong interactions. The LHCb experiment, with the large production cross-sections, its hadron identification capabilities and triggers optimized to collect events with bottom and charm quarks, has reached a new level of sensitivity in detecting new, interesting states in baryon and meson sectors. Some of these states have been expected, like newly discovered five excitations of the doubly-strange and charmed baryon. Some of them are spectroscopic puzzles, like potential pentaquark states or, reported recently, four tetraquark candidates with hidden charm and strangeness. I will discuss the LHCb results on heavy hadrons and put them in a broader context of hadronic spectroscopy.

**Igor Klebanov**, Department of Physics, Princeton University

**"Unusual quasiparticle correlation in graphene"**

Philip Kim,Harvard University

Philip Kim,

Interactions between particles in quantum many-body systems can lead to a collective behavior. In a condensed matter system consisting of weakly interacting particles, a propagating particle interacting with its surroundings can be viewed as a ‘dressed’ quasiparticle with renormalized mass and other dynamic properties. The lack of screening enables strong Coulomb interactions between charged particles, leading to new collective dynamics. In this talk, I will discuss three examples concerning strongly interacting quasiparticles in graphene. In the first example, it will be shown that the thermally populated electrons and holes to realize Dirac fluid, where a huge violation of Wiedemann-Franz law is observed. The second example is realizing magnetoexcitons to correlated** **quasiparticles in quantized Landau levels to form magnetoexcitons, which can condense into Bose-Einstein condensation. Finally, we will also discuss another way of correlated quasiparticles in graphene using superconducting proximity effect. Here, we employ the crossed Andreev reflection across thin Type II superconducting electrodes to correlated spatially separated quasiparticles. Under strong magnetic fields, the quantum Hall edge states can carry these quasiparticles.

**N. Phuan Ong**, Department of Physics, Princeton University

4:00 p.m., Thursday, April 27, 2017

**“LHC at 13 TeV”**

**James Olsen**, Princeton University

**Dan Marlow**, Department of Physics, Princeton University

## 42nd annual Donald R. Hamilton Lecture

### 8:00 p.m., Thursday, May 4, 2017

**McDonnell Hall, Room A02**

"Topological Phases of Matter"

**Speaker: Charles Kane, University of Pennsylvania**

Matter can arrange itself in the most ingenious ways. In addition to the solid, liquid and gas phases that are familiar in classical physics, quantum mechanics enables the existence of electronic phases of matter that can have both exotic and useful properties. In the last century, the thorough understanding of the simplest quantum electronic phase - the electrical insulator - enabled the development of the solid state electronics technology that is ubiquitous in today's information age. In the present century, new "topological" electronic phases are being discovered that may enable future technologies by allowing the seemingly impossible to occur: indivisible objects, like an electron or a quantum bit of information, can be split into two, allowing mysterious features of quantum mechanics to be harnessed. Our understanding of topological phases, which was celebrated by the 2016 Nobel Prize in physics, builds on deep ideas in mathematics. We will try to convey that they are as beautiful as they are fundamental.

Host: **Paul Steinhardt, Princeton Center for Theoretical Science**