This award supports theoretical studies and corresponding educational activities in condensed matter physics. The focus is on ostensibly ordered states of matter, characterized by an exceptionally "soft" elasticity, and are consequently strongly and qualitatively affected by fluctuations and local heterogeneity. The PI will study a number of experimentally motivated examples of such states, realized in a variety of unusual contexts.
The PI will explore various states of matter including: uniaxially periodically ordered superfluids, such as the Larkin-Ovchinnikov state of a species-imbalanced paired superconductor and a bosonic smectic supersolid, and helical ground states of frustrated centrosymmetric and chiral noncentrosymmetric magnets.
The PI will formulate a low-energy sigma-model description of such states, and will use it to investigate their low-energy properties and related phase transitions. Some of the key ingredients that will be incorporated are required Goldstone mode nonlinearities, novel topological defects, and new states arising from their proliferation, quantum dynamics, coupling to fermionic degrees of freedom, and the effects of various external fields.
Another focus of the research is a class of condensed matter systems that exhibit bulk ordered states subjected to a random surface pinning, a liquid crystal cell with a "dirty" glass substrate being a prominent example. The PI will develop models for such systems and extensively explore a number of fundamental and applied aspects, including: the stability of phases to surface pinning, statistics and length scales characterizing distortions, topological defects, and effects of finite cell thickness and external fields.
The research is planned to address real experimental problems and pushing the frontiers of theoretical condensed matter physics, the research will contribute to synergism between otherwise disparate subfields. This award supports educational and outreach efforts including: curriculum development of condensed matter physics, developing sophomore Modern Physics courses, and mentoring teachers, high school, and undergraduate students.
NONTECHNICAL SUMMARY
This award supports theoretical studies and corresponding educational activities to study various new states of matter that are linked by a common property. These states of matter are considered to be "soft" and particularly susceptible to fluctuations whether they are thermal fluctuations described by statistical physics or quantum fluctuations that arise as a consequence of Heisenberg's famous uncertainty principle. Examples include magnets and superfluids, a quantum state of matter that is characterized by fluid flow without loss. Superfluids arise in a number of contexts. Superfluids involving charged particles are called superconductors and encompass wide class of materials. These "superstates" can also be realized by gases of atoms cooled to nearly the absolute zero of temperature using laser beams. The PI will study a number of experimentally motivated examples of such states, realized in a variety of unusual contexts.
Some soft states of matter are also sensitive to impurities. A liquid crystal display with a "dirty" glass substrate might be a prominent example. The random impurities on the glass substrate can disrupt how the molecules of the liquid crystal orient themselves. The PI will use advanced theoretical techniques to study such systems with the aim of advancing fundamental understanding of how nature works.
This research is planned to address real experimental problems and to push the frontiers of theoretical condensed matter physics. The research will contribute to synergism between otherwise disparate subfields. It may also contribute to the foundations of new technologies as the manipulation of states of matter and materials may lead to new phenomena that can form the basis for future device technologies. This award also supports educational and outreach efforts including: curriculum development of condensed matter physics, developing sophomore Modern Physics courses, and mentoring teachers, high school, and undergraduate students.
