Welcome to the home page of the condensed matter theory group of Sungkit Yip. Our group conducts research in many areas of condensed matter theory, including superconductors, superfluids, cold atomic gases, and quantum magnets. Please see Research for more information.
Superconductivity is one of the most amazing phenomena. In the original theory by Bardeen, Cooper and Schrieffer (BCS), superconductivity is described by an order parameter Ψ which is a single component complex scalar. We research on superconductors with order parameters that are multi-component, part of a vector field etc. These superconductors have multiple phase transitions, distinct topological excitations etc and thus have qualitative behaviors from the single component case.
The “traditional” superfluid 4He is in a sense analogous to BCS superconductors in that it can also be described by an order parameter which is a single component complex scalar. Cold bosonic atomic gases now offer us with more superfluids as the atoms undergo Bose-Einstein condensation at low temperatures. In addition, these atoms can have internal degrees of freedom due to their hyperfine spins, thus offering us again with more examples with multi-component superfluids which we can study via different experimental tools not available to traditional condensed matter systems.
Spins in magnetic systems can order at low temperatures – well-known examples are ferromagnets and antiferromagnets. In those cases, the spins can be taken as classical vectors pointing in some preferred fixed directions in their ordered state, and are referred to as classical magnetic systems. However, spins are actually quantum mechanical objects. We research into systems where such quantum effects are important, with unusual ground states which exhibit quantum entanglement and exotic excitations.
Group Leader
Sungkit Yip 葉崇傑
Distinguished Research Fellow
Personal Webpage @IoP Personal Webpage @IAMSWe welcome applications as research assistants or postdocs from anyone who is hard-working, enthusiastic about research in physics and willing to take on challenges. Please write to yip@phys.sinica.edu.tw.
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