Daily Calendar - Physics Department, Princeton University

Events - Daily

<< November 09, 2012 >>

Friday, November 09
PCTS Series Nonequilibrium Physics Strongly Interacting Matter & Light, Michel Devoret Yale Univ. Parametric Amplification of Quantum Signals Quantum Mechanics puts a limit on how small the degradation of information passing through an amplifier can be. It is known theoretically that the minimum noise added by an amplifier to the signal amounts, in phase preserving mode, to at least half a photon at the signal frequency. Is it possible to construct an amplifier working at microwave frequencies that would reach this quantum limit and still be practical in terms of gain, bandwidth and dynamical range? We will present recent work by our group aiming at answering this question, which is of crucial importance for the readout of solid state qubits, and more generally, for measurement of very weak electromagnetic signals in various areas of science. PCTS Seminar Room · 11:00 a.m.–12:30 p.m.
High Energy Theory Seminar - IAS - Michele Del Zotto, SISSA - “Evidences for D(G,s) Theories” In the past three years some aspects of the duality in between representation theory of associative algebras and N=2 supersymmetric theories in four dimensions have proven to be crucial for understanding the so-called BPS-quiver theories. Very recently, as a natural consequence of the 2d/4d correspondence combined with the aforementioned duality, evidences for the existence of infinitely many N=2 superconformal field theories have been found: For each simple simply-laced Lie group G, there exists an infinite tower of N=2 SCFT's having (at least) flavor group G. These theories are labeled D(G,s), where s is a positive integer. In the talk, after a review of the formalism, I will discuss such evidences, and explain some of the basic properties of these N=2 superconformal models. Bloomberg Lecture Hall · 1:30 p.m.– 2:30 p.m.

Friday, November 09

PCTS Series Nonequilibrium Physics Strongly Interacting Matter & Light, Michel Devoret Yale Univ. Parametric Amplification of Quantum Signals
Quantum Mechanics puts a limit on how small the degradation of information passing through an amplifier can be. It is known theoretically that the minimum noise added by an amplifier to the signal amounts, in phase preserving mode, to at least half a photon at the signal frequency. Is it possible to construct an amplifier working at microwave frequencies that would reach this quantum limit and still be practical in terms of gain, bandwidth and dynamical range? We will present recent work by our group aiming at answering this question, which is of crucial importance for the readout of solid state qubits, and more generally, for measurement of very weak electromagnetic signals in various areas of science.
PCTS Seminar Room · 11:00 a.m.–12:30 p.m.

High Energy Theory Seminar - IAS - Michele Del Zotto, SISSA - “Evidences for D(G,s) Theories”
In the past three years some aspects of the duality in between representation theory of associative algebras and N=2 supersymmetric theories in four dimensions have proven to be crucial for understanding the so-called BPS-quiver theories. Very recently, as a natural consequence of the 2d/4d correspondence combined with the aforementioned duality, evidences for the existence of infinitely many N=2 superconformal field theories have been found: For each simple simply-laced Lie group G, there exists an infinite tower of N=2 SCFT's having (at least) flavor group G. These theories are labeled D(G,s), where s is a positive integer. In the talk, after a review of the formalism, I will discuss such evidences, and explain some of the basic properties of these N=2 superconformal models.

Bloomberg Lecture Hall · 1:30 p.m.– 2:30 p.m.