Physics Colloquium: Olga Goulko, "Controlled results in quantum many-body physics: from a dream to reality"
Mar 29, 2017
from 04:00 PM to 05:00 PM
|Contact Name||Myriam Sarachik|
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Wednesday, March 29
Olga Goulko, University of Massachusetts, Amherst
TITLE: Controlled results in quantum many-body physics: from a dream to reality
Many interesting systems in modern condensed matter physics, such as strongly correlated fermions, are too complex to be dealt with by purely analytical methods because of the lack of small parameters. In this talk, I will discuss the power of the diagrammatic technique, which allows us to address problems in many-body physics (and indeed many other areas of physics!) directly from first principles. I will show how physical quantities can be obtained from the diagrammatic expansion in a controlled and systematically improvable manner using numerical algorithms, such as quantum Monte Carlo. In this sense, simulations can be viewed as "numerical experiments" probing the system and making quantitative predictions about its properties. In combination with analytical methods they also offer an exciting new way to address fundamental questions. We can test previously uncontrolled assumptions and explicitly check which properties of a model are necessary to produce certain features, and which are irrelevant. I will illustrate the successes and challenges of diagrammatic Quantum Monte Carlo on several examples from atomic physics.
The speaker is a candidate for the position of Assistant/Associate Professor of Physics.