Events

Filter by:

Limit to events where the first date of the event:
Date range
Limit to events where the first date of the event:
Limit to events where the title matches:
Limit to events where the type is one or more of:
Limit to events tagged with one or more of:
Limit to events where the audience is one or more of:
Thursday, March 2, 2017 1:30 pm - 1:30 pm EST (GMT -05:00)

Seminar: Zhexuan Gong

Harnessing quantum systems with long-range interactions

Zhexuan Gong, University of Maryland, College Park

A distinctive feature of atomic, molecular, and optical systems is that interactions between particles are often long-ranged. Together with control techniques from quantum optics, these long-range interacting systems could be harnessed to achieve faster quantum information processing and to simulate novel quantum many-body phenomena. A

Monday, March 6, 2017 2:30 pm - 2:30 pm EST (GMT -05:00)

Colloquium: Pravesh Kothari

Quantum Entanglement, Sum-of-Squares and the Log-Rank Conjecture

Pravesh Kothari, Princeton University

This talk will be about a sub-exponential time algorithm for the Best Separable State (BSS) problem. For every constant \eps>0, we give an exp(\sqrt(n) \poly log(n))-time algorithm for the 1 vs 1-\eps BSS problem of distinguishing, given an n^2 x n^2 matrix M corresponding to a quantum measurement, between the case that there is a separable (i.e., non-entangled) state \rho that M accepts with probability 1, and the case that every separable state is accepted with probability at most 1-\eps.

Thursday, March 9, 2017 10:30 am - 10:30 am EST (GMT -05:00)

Seminar: Shalev Ben-David

The Power of Randomized and Quantum Computation

Shalev Ben-David, Massachusetts Institute of Technology

Randomized and quantum computing offer potential improvements over deterministic algorithms, and challenge our notion of what should be considered efficient computation. A fundamental question in complexity theory is to try to understand when these resources help; on which tasks do randomized or quantum algorithms outperform deterministic ones?

In this talk, I will describe some of my work investigating this question, primarily in the query complexity (blackbox) model.

Friday, March 10, 2017 11:45 am - 11:45 am EST (GMT -05:00)

RAC1 Journal Club/Seminar Series:

Fabrication of Diamond Based Fabry-Perot Cavities: Boring is beautiful

Madelaine Liddy, IQC

Nitrogen-vacancy (NV) centers in diamond are promising candidates for acting as the nodes in a quantum network. Previous work has demonstrated the entanglement between two NV centers over a distance of 1.3km for the loophole-free bell test in 2015.

Monday, March 13, 2017 2:30 pm - 2:30 pm EDT (GMT -04:00)

Colloquium: David Allcock

Trapped-ion quantum logic with near-field microwave-driven gates

David Allcock, National Institute of Standards and Technology, Boulder

Hyperfine qubits in laser-cooled trapped atomic ions are one of the most promising platforms for general-purpose quantum computing. Magnetic field-insensitive ‘clock states’ and near-infinite lifetimes allow for minute-long memory coherence times as well as qubit frequencies that are in the convenient microwave domain [1]. Most work on these qubits has so far focussed on using lasers for gate operations, however there are several schemes that offer the prospect of performing all coherent operations using purely electronic methods [2,3].

Tuesday, March 14, 2017 10:00 am - 10:00 am EDT (GMT -04:00)

Seminar: Leena Aggarwal

Tip induced superconductivity at mesoscopic point contacts on topological semimetals

Leena Aggarwal, Indian Institute of Science Education and Research, Mohali

I will present the observation of a new phase of matter, tip-induced superconductivity (TISC), that emerges only under mesoscopic metallic point contacts on topologically non-trivial semimetals like a 3-D Dirac semimetal Cd3As2, and a Weyl semimetal, TaAs. From theoretical considerations, it is believed that such semimetals exist near topological phase boundaries.

Monday, March 20, 2017 2:30 pm - 2:30 pm EDT (GMT -04:00)

Seminar: Rakesh Tiwari

Robust quantum optimizer with full connectivity

Rakesh Tiwari, McGill University

Quantum phenomena have the potential to speed up the solution of hard optimization problems. For example quantum annealing, based on the quantum tunneling effect, has recently been shown to scale exponentially better with system size as compared with classical simulated annealing. However, current realizations of quantum annealers with superconducting qubits face two major challenges. First, the connectivity between the qubits is limited, excluding many optimization problems from a direct implementation.

Wednesday, March 22, 2017 11:00 am - 11:00 am EDT (GMT -04:00)

Seminar: Mohammad Ansari

Entropy measurement in quantum systems

Dr. Mohammad Ansari, Peter Grünberg Institute, and Jülich-Aachen Research Alliance Institute (JARA)

Entropy is an important information measure. A complete understanding of entropy flow will have applications in quantum thermodynamics and beyond; for example it may help to identify the sources of fidelity loss in quantum communications and methods to prevent or control them. Being nonlinear in density matrix, its evaluation for quantum systems requires simultaneous evolution of more-than-one density matrix.

Friday, March 24, 2017 11:45 am - 11:45 am EDT (GMT -04:00)

RAC1 Journal Club/Seminar Series - Special Seminar

Optical manipulation of polariton in semiconductor microstructures

Félix Marsault, French National Center for Scientific Research

Cavity polaritons are bosonic quasiparticles arising from the strong coupling between photons and excitons. They can massively occupy a single quantum state in the regime of polariton lasing [1], showing particular properties such as long coherence times [1], long range spatial coherence [1] and a linearly polarized emission [1,2,3]. Moreover, they possess strong excitonic nonlinearities and thus provide a new platform for elliptical photonic manipulation, with the demonstration of a polariton spin switch [4], polariton transistors [5] and the proposal of other proof-of-principle operations for elliptical integrated logic circuits [6].