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The main topic of Ben Hunt's (CMU) talk is superconductivity in two dimensions.

He describes the new approach he developed with his team to make superconductors with the van der Waals heteromaterial NbSe2...and the surprising observation of a metallic state at non-zero temperatures.
This state is characterized by a resistance that is finite, independent of the temperature, and has a power-law dependence on the magnetic field.

Cyrus Umrigar (Cornell University) gives an in-depth description of various variational and projector Quantum Monte Carlo (QMC) methods that are used to computationally solve problems in chemistry and physics. He also addresses some of the current challenges in method development and application, namely the sign problem, as well as the current approaches to overcome the issue. Several methods are thus compared and contrasted throughout the lecture.

Nader Engheta (University of Pennsylvania) talks about some of the aspects of near-zero optics and applications in "extreme" optical materials. He introduces the notion of ‘static optics’, a state in which the the electric and magnetic fields are temporally dynamic but decoupled. This occurs in materials where both the relative effective permittivity and permeability attain near-zero values. Such "Near-Zero" structures show promise as platforms for quantum emitters, long-range entanglement, and quantum interference.

Martin Zwierlein (M.I.T.) talks about strongly interacting fermi gases of atoms and molecules. He introduces NaK, a chemically stable fermionic molecule studied in his group and explains the process of generating this molecule in the ground state with a high conversion efficiency and reasonable lifetime. He also describes the first studies of the hyperfine states of this new quantum system and how with two such states, they can build a molecular clock.

Martin Zwierlein (M.I.T.) talks about strongly interacting fermi gases of atoms and molecules. He introduces NaK, a chemically stable fermionic molecule studied in his group and explains the process of generating this molecule in the ground state with a high conversion efficiency and reasonable lifetime. He also describes the first studies of the hyperfine states of this new quantum system and how with two such states, they can build a molecular clock.

Doug Natelson (Rice University) talks about heating and vibrations at the molecular level. Non equilibrium heating is of much interest in physics although it is still difficult to obtain information about the local electronic or vibrational distribution. He therefore proceeds to describe the approach developed by his group towards simultaneous electron transport and Surface Enhanced Raman Spectroscopy with plasmons at the molecular-scale.

Xiao Yang Zhu (Columbia University) talks about many body coherent processes in semiconductors brought about by light-matter interactions with applications in solar energy conversion. He describes the recent experimental detection of phonon-assisted Auger recombination as well as the nature of the multi-exciton state and the role of vibronic coherent and incoherent rate processes in singlet fission.

Strong repulsive interactions and potential in homogeneities both tend to localize Fermions on a lattice and lead to loss of superconductivity. The natural question that comes up is whether they compete or complement each other when both are present in a system at the same time. In this talk, we will use a effective Hamiltonian approach which treats both interactions and in homogeneities on the same footing to look at two systems: (a) the Ionic Hubbard Model at half-filling, where a staggered potential on a bipartite lattice competes with interactions to delocalize charge and give birth to a novel superconductor. The superconducting Tc scales with the bandwidth of the system and shows a non-monotonic behaviour with the staggered potential, (b) the disordered Hubbard model away from half-filling, where weak disorder competes with strong interaction to preserve superconductivity, but strong disorder complements interactions leading to sudden death of superconductivity in this system.

Jeremy Levy and Aude Marjolin present the Pittsburgh Quantum Institute to the Swanson School of Engineering.

March 3, 2016

Exascale HPC, Big Data, and Quantum Computing in Rocket Science

Peyman Givi, PhD
Distinguished Professor of Mechanical Engineering and Materials Science
Swanson School Of Engineering
University of Pittsburgh

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