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Sagi Yoav logo, back to home page

Research

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Here are introductions to some of our current and past research subjects:

Today, our main interest is in studying strongly interacting Fermi gases. Want to know why? keep reading.

With the discovery of superconductivity by Kammerling Onnes in 1911, everyone’s imagination was sparked by the possible applications of current flowing without resistance. However, these applications were deemed less feasible than it was hoped by the ultracold temperatures (below -250C ) that had to be reached by materials in order to obtain superconductivity. Scientific interest was renewed when in 1986 high-temperature (below -100C) superconductors were discovered, and indeed today these high-temperature superconductors are used in scientific applications, for example to create very powerful magnets. Scientists today dream of achieving superconductivity at room temperature; however, although the mechanism by which low-temperature superconductivity operates is quite well understood, there is still much to be desired as far as our understanding of high temperature superconductivity goes. This is where our group’s research comes into play. We focus on understanding collective many-body phenomena of strongly interacting fermions, the basic building blocks of a superconducting materials; however, we do this in a gas, Potassium 40, which is cooled to very low temperatures using lasers and magnetic fields, until the fermions form pairs, and subsequently attain a state of matter called a Bose-Einstein condensate. Our system is unique in that it is a very good model system, which enables us to control many relevant parameters by using different configurations of lasers and magnetic field- unlike in a high-temperature superconductor where the attributes of the material are fixed. Thus, we can investigate various configurations of this condensate, with the hope of gaining a better understanding of the mechanism at the heart of high temperature superconductivity.

Our field is sometimes referred to as “quantum simulation”, since one system is used to simulate and study the physics of another system, which might be much less accessible or controllable. A good review paper on the subject can be found here. Personally, I don’t think this is the most accurate description of what we do; We don’t study the physics of ultracold fermions because it simulates the physics of another system. It deserves studying and exploring by its own merit, and in the same time happen to be relevant to many other similar many-body systems.

contact information of Dr Yoav Sagi: yoav.sagi[AT]physics.technion.ac.il