Since 2002 Perimeter Institute has been recording seminars, conference talks, and public outreach events using video cameras installed in our lecture theatres. Perimeter now has 7 formal presentation spaces for its many scientific conferences, seminars, workshops and educational outreach activities, all with advanced audio-visual technical capabilities. Recordings of events in these areas are all available On-Demand from this Video Library and on Perimeter Institute Recorded Seminar Archive (PIRSA). PIRSA is a permanent, free, searchable, and citable archive of recorded seminars from relevant bodies in physics. This resource has been partially modelled after Cornell University's arXiv.org.
We studied t1-t2-J1-J2 model on Honeycomb lattice at finite doping. We find that when t_1 is very small, the t1-t2-J1-J2 model on Honeycomb lattice may be in a supperconducting phase. Such a supperconducting phase is not driven by the pairing, but by entanglement.
The Large Hadron Collider (LHC) at CERN has already yielded deep insights into nature including the discovery of the Higgs boson. Later this year, it will start operating at its full energy of 14 TeV. What will it be searching for? What might it discover? This talk will explore the LHC in 2015 and its beyond.
In describing condensed matter, some well established paradigms have allowed much progress to be made in understanding and using materials. But in the last 15 - 20 years, new materials, such as heavy fermions, high temperature superconductors, and now charge density wave-supporting materials, have been shown to require new paradigms in describing them. While much progress has been achieved in that time, we still do not have a widely accepted theoretical description of the nature of their electronic excitations.
We discuss two basic principles to unify the understanding of both cuprates and iron-based superconductors: (1) the correspondence principle— the short range magnetic exchange interactions and the Fermi surfaces act collaboratively to achieve high Tc superconductivity and determine pairing symmetries; (2) the selective magnetic pairing rule: the superconductivity is only induced by the magnetic exchange couplings from the superexchange mechanism through cation-anion-cation chemical bondings but not those from direct exchange couplings resulted from the direct cation's d-d chemical bondings