This series covers all areas of research at Perimeter Institute, as well as those outside of PI's scope.
This will be an introductory talk about Topological Quantum Computation. TQC is attractive because it is intrinsicaly decoherence free. We introduce the basic notions, such as non abelian anyons, quantum symmetries and topological order. A topologically ordered phase is a gapped phase in which the basic degrees of freedom are of a topological nature (denoted as anyons), charactetized by their fusion and braiding properties. If time permits possible implementations based on Quantum Hall systems will be discussed as well.
Laser cooling and precision spectroscopy provide powerful tools for exploring quantum measurement and metrology using atoms as sensors. In this talk I will discuss our ongoing work to bring together abstract ideas of quantum parameter estimation and concrete physical details of atom-photon interactions in the specific context of magnetometry. I will also present some new ideas on how laser probing of cold atoms could provide a basis for developing entanglement-enhanced spin gyroscopes.
The manifold of pure quantum states can be regarded as a complex projective space endowed with the unitary-invariant Fubini-Study metric.
The physical characteristics of a given quantum system can then be represented by a variety of geometrical structures that can be identified in this manifold.
This talk will review a number of examples of such structures as they arise in the state spaces of spin-1/2, spin-1, spin-3/2, and spin-2 systems, and various types of entangled systems, all of which have fascinating and beautiful geometries associated with them.
The role of outflows in global star formation processes has become hotly debated even as fundamental questions about the nature of these outflows continues to receive attention. In this talk I discuss both problems and new approaches to their resolution. Astrophysical outflows have always been a subject at the forefront of the numerical technologies and in the first act of the talk I introduce AstroBEAR, a new Adaptive Mesh Refinement MHD tool developed at Rochester for the study of star formation outflow issues.
One of the cool, frustrating things about quantum theory is how the once-innocuous concept of "measurement" gets really complicated. I'd like to understand how we find out about the universe around us, and how to reconcile (a) everyday experience, (b) experiments on quantum systems, and (c) our theory of quantum measurements. In this talk, I'll try to braid three [apparently] separate research projects into the beginnings of an answer.
Quantum field theory in curved spacetime (QFTCS) is the theory of quantum fields propagating in a classical curved spacetime, as described by general relativity. QFTCS has been applied to describe such important and interesting phenomena as particle creation by black holes and perturbations in the early universe associated with inflation. However, by the mid-1970\'s, it became clear from phenomena such as the Unruh effect that \'particles\' cannot be a fundamental notion in QFTCS.
I will discuss an alternative approach to simulating Hamiltonian flows with a quantum computer. A Hamiltonian system is a continuous time dynamical system represented as a flow of points in phase space. An
alternative dynamical system, first introduced by Poincare, is defined
in terms of an area preserving map. The dynamics is not continuous but discrete and successive dynamical states are labeled by integers rather than a continuous time variable. Discrete unitary maps are
naturally adapted to the quantum computing paradigm. Grover's
Modern motivations for extra spacetime dimensions will be presented, in particular the surprising AdS/CFT connection to particle compositeness. It will be shown how highly curved, "warped", extra-dimensional geometries can naturally address several puzzles of fundamental physics, including the weakness of gravity, particle mass hierarchies, dark matter, and supersymmetry breaking. The possibility of direct discovery of warped dimensions at
The progress in neutrino physics over the past ten years has been
tremendous: we have learned that neutrinos have mass and change flavor. I will pick out one of the threads of the story-- the measurement of flavor oscillation in neutrinos produced by cosmic ray showers in the atmosphere, and its confirmation in long distance beam experiments. I will present the history, the current state of knowledge, and how the next generation of high intensity beam experiments will address some of the remaining puzzles.
Among the possible explanations for the observed acceleration of the universe, perhaps the boldest is the idea that new gravitational physics might be the culprit. In this colloquium I will discuss some of the challenges of constructing a sensible phenomenological extension of General Relativity, give examples of some candidate models of modified gravity and survey existing observational constraints on this approach.