Events

Abstract

Evidence is presented for the finite wave vector crossing of the two lowest one-dimensional spin-split subbands in quantum point contacts fabricated from two-dimensional hole gases with strong spin-orbit interaction. This phenomenon offers an elegant explanation for the anomalous sign of the spin polarization filtered by a point contact, as observed in magnetic focusing experiments. Anticrossing is introduced by a magnetic field parallel to the channel or an asymmetric potential transverse to it.

Aashish Clerk, McGill University

Abstract

Slow neutrons are used in a very broad spectrum of scientific investigations. I will discuss how neutrons are liberated from nuclei and lowered in energy to regimes of interest. I will also discuss some examples of experiments, mainly motivated by questions in nuclear/particle/astrophysics.

Helen Fay Dowker, Imperial College London

Abstract

We provide the first two-party protocol allowing Alice and Bob to evaluate privately even against active adversaries a completely positive, trace-preserving map F, given as a quantum circuit, upon their joint quantum input state. Our protocol leaks no more to any active adversary than an ideal functionality for F provided Alice and Bob have the cryptographic resources for active secure two-party classical computation.

Pragya Shukla, Indian Institute of Technology Kharagpur

David Gosset, Institute for Quantum Computing (IQC)

Abstract

A welded tree is a graph consisting of two binary trees "welded"
together with a random cycle between the leaves. In 2003, Childs et
al. showed that a quantum walk has an exponential speedup over
classical algorithms when traversing the graph from one root vertex to
the other. I give evidence that related graphs also have an
exponential gap between classical algorithms and the quantum walk.

Vadym Kliuchnikov, Institute for Quantum Computing (IQC)

Abstract:

TBD