Trivedi Group

The research in Professor Nandini Trivedi’s group focuses on the effects of strong interactions in condensed matter systems and ultracold atoms in optical lattices. The basic idea is to understand how electrons and atoms get organized at very low temperatures and how new phases of matter emerge. For example, we examine quantum phase transitions between superfluids and Mott insulators in optical lattices and also how fermions become entangled into novel spin liquid states. We are also involved many new avenues of research, including phases in complex oxides, such as high T_c superconductors and double perovskites, emerging form the interplay of charge, spin and orbital degrees of freedom. Our approach is to combine different types of quantum Monte Carlo simulations with analytical methods.

Our area of research is in theoretical and computational condensed matter physics. The two main areas of research under condensed matter that this group engages in are cold atoms and complex materials. We focus on a number of still unsolved, intellectually stimulating problems that have strong connections with experiments. There is also the possibility of new applications.

Ultra-cold atoms is a recent field, having only emerged in the past decade at the intersection of atomic and molecular physics and condensed matter physics. Some of the big questions we ask are related to the new kinds of ways in which atoms get organized at low temperatures. Specifically, we work to understand quantum phase transitions in optical lattices, such as between superfluid and Mott insulators driven by increasing the repulsive interactions between bosons. In fermionic systems, it is possible to see the emergence of a Mott insulator with a gap to charge excitations and showing antiferromagnetic order with increasing repulsive interactions. We also show how in fermions with attractive interactions there is a clear separation between the temperature at which pairing between fermions sets in and where the pairs develop long range phase coherence.

Thus we see that not only can we have transitions between phases by raising the temperature but also at zero temperature by quantum effects.

We also explore new avenues of research on complex materials called perovskites that are on the brink of many unusual properties like ferroelectricity, magnetism, and superconductivity. The high temperature superconductors and double perovskites are examples of such compounds that we research. Ultimately, we hope to find how to exploit and control these materials and their amazing properties. We collaborate with experimental physicists, chemists, and materials scientists on these topics.