Current graduate students

Monday, July 11, 2016 2:30 pm - 2:30 pm EDT (GMT -04:00)

Colloquium: Jess Riedel

Where are the branches in a many-body wavefunction?

Jess Riedel, Perimeter Institute

When the wavefunction of a macroscopic system (such as the universe) unitarily evolves from a low-entropy initial state, we expect that it develops quasiclassical "branches", i.e., a decomposition into orthogonal components each taking well-defined, distinct values for macroscopic observables. Is this decomposition unique? Can the number of branches decrease in time?

Wednesday, June 8, 2016 1:30 pm - 1:30 pm EDT (GMT -04:00)

Seminar: Tom Stace

Correlated decay in driven quantum systems

Tom Stace, University of Queensland, Australia

Gate defined quantum dots are "artificial atoms", with well defined energy levels. They interact strongly with microwave resonators, and with the solid-state environment in which they live. These systems can exhibit population inversion, single-atom masing and other phenomena familiar to the quantum optics community. The environment also produces higher-order correlated decay processes, which are typically not included in quantum-optical Lindblad master equations.

Monday, June 27, 2016 2:30 pm - 2:30 pm EDT (GMT -04:00)

Colloquium: Robert Myers

Information, Holography & Gravity

Robert Myers, Perimeter Institute

In science, new advances and insights often emerge from the confluence of different ideas coming from what appeared to be disconnected research areas. The theme of my talk will review an ongoing collision between the three topics listed in my title which has been generating interesting new insights about the nature of quantum gravity, as well as variety of other fields, such as condensed matter physics and quantum field theory.

Friday, June 24, 2016 2:00 pm - 2:00 pm EDT (GMT -04:00)

Seminar: Bhaskaran Muralidharan

The role of dual-nuclear baths on singlet-triplet dynamics in a double quantum dot

Bhaskaran Muralidharan, Indian Institute of Technology Bombay

A deeper understanding of electronic transport phenomena at the nanoscale is a cross-disciplinary effort that intertwines quantum dynamics, electronic structure and statistical physics.

Thursday, May 12, 2016 1:00 pm - 1:00 pm EDT (GMT -04:00)

Seminar: Bruno Huttner

Quantum Technologies for Cyber Security: from threats to solutions

Bruno Huttner, ID Quantique, Switzerland

Recent developments in quantum computers have spurred renewed interest in quantum-safe solutions for information security [1]. It is now widely accepted that the current public key infrastructures, which are the foundation of cyber security, will not withstand the arrival of the quantum computer [2], [3], and that this arrival will occur with high probability within the next ten to fifteen years. New solutions are called for, and these solutions should at least be partly based on quantum technologies.

Friday, May 6, 2016 11:00 am - 11:00 am EDT (GMT -04:00)

Seminar: Alexei Bylinskii

Friction under microscope in a trapped-ion optical-lattice emulator

Alexei Bylinskii, Massachusetts Institute of Technology

Friction is the ubiquitous mechanical process of sticking and energy dissipation at the interface between objects. Despite its technological and economic significance, friction remains poorly understood, being a non-linear, out-of-equilibrium, many-body process. According to the widely known empirical laws of friction, it is proportional to the load on the interface and independent of velocity.

Monday, April 25, 2016 1:00 pm - 1:00 pm EDT (GMT -04:00)

Seminar: Wayne Cheng-Wei Huang

Multicolor quantum channels for nanowire-based photonic devices 

Wayne Cheng-Wei Huang, University of Nebraska-Lincoln 

Using a two-color laser field and tungsten nanotips, we showed that multicolor quantum channels led to a twofold increase in quantum efficiency. By gating quantum efficiency with pulse delay, optical control of electron photoemission was attained for fields with modest intensity. In this talk, I will discuss the observed effect and potential applications for nanowire-based photonics transistors and ultrafast spin-polarized electron sources. 

Wednesday, June 22, 2016 7:00 pm - 7:00 pm EDT (GMT -04:00)

The detection of gravitational waves on earth

Public lecture by Bill Unruh, The University of British Columbia

On February 11, 2016 it was announced that gravitational  waves have been detected affecting an instrument on earth. In addition to the realization of a 100 year old prediction the astounding sensitivity of the detector demanded the approaching and overcoming of seemingly fundamental quantum limits on measuring the motion of 25Kg masses. Quantum mechanics is usually thought of applying only to the very small (zeptogrammes and nanometers).

Thursday, April 21, 2016 12:00 pm - 12:00 pm EDT (GMT -04:00)

Seminar: Cheng Guo

Tensor Rank and Entanglement Transformation between Multipartite Pure States

Cheng Guo, Tsinghua University & University of Technology, Sydney

The tensor rank of a symmetric tensor is equal to the polynomial rank of some homogeneous polynomial. I will introduce the isomorphism between symmetric states and homogeneous polynomials.

Monday, April 18, 2016 2:30 pm - 2:30 pm EDT (GMT -04:00)

Colloquium: Lidia del Rio

Finding non-signalling agents and subsystems in global theories

Lidia del Rio, University of Bristol

How can we find operational notions of local agents within a global theory? In this talk, I will present an operational way to model the effective state spaces of individual agents, as well as the range of their actions. I will then address the aspects of locality relevant to derive independence and non-signalling conditions between agents. This approach establishes an operational connection between local action and local observations, and gives a global interpretation to concepts like discarding a subsystem or composing local functions.