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Monday, January 17, 2011 12:30 pm - 1:30 pm EST (GMT -05:00)

Mohammad Ansari: The Kondo effect

Mohammad Ansari, Institute for Quantum Computing

Abstract

With lowering temperature, a qubit may become strongly coupled to the reservoirs. This can result into some exotic situations such as: the appearance of full conductivity instead of current blockade in a quantum dot, increasing resistivity with lowering temperature in a metal, and the appearance of microresonators in the critical current noise in a Josephson junction. In this talk, some of these phenomena are discussed.

Friday, November 19, 2010 3:30 pm - 4:30 pm EST (GMT -05:00)

David Jao: Constructing Elliptic Curve Isogenies in Quantum Subexponential Time

Given two elliptic curves over a finite field having the same cardinality and endomorphism ring, it is known that the curves admit an isogeny (a.k.a. algebraic map) between them, but finding such an isogeny is believed to be computationally difficult. The fastest known classical algorithm for this problem requires exponential time, and prior to our work no faster quantum algorithm was known. We show that this problem can be solved in subexponential time on a quantum computer, assuming the

Tuesday, November 9, 2010 12:00 pm - 1:00 pm EST (GMT -05:00)

Sevag Gharibian: Approximation algorithms for QMA-complete problems

Approximation algorithms for classical constraint satisfaction problems are one of the main research areas in theoretical computer science. A natural generalization of constraint satisfaction problems to the quantum setting is the local Hamiltonian problem, which is of significant interest to both complexity theorists and to physicists studying properties of physical systems alike. In this talk, we define a natural approximation version of the local Hamiltonian problem and initiate its study. We present two main results.