Anyons in 2D Materials and Cold Atomic Gases

Background: The unparalleled potential capabilities of quantum sensors and quantum computers hinge upon finding systems that can be well controlled and robust against decoherence. Anyons are quasiparticles with fractional quantum statistics that can exist in low-dimensional systems and whose topological properties allow one to create quantum states that are protected from many sources of decoherence. The experimental evidence of the fractional quantum Hall effect (FQHE) was a landmark demonstration of topological order and fractional (anyonic) statistics in a two-dimensional electronic system. However, the fragility of the FQHE states, in which interesting anyons can exist, have prevented this approach from advancing despite decades of improvements in material quality. On the other hand, the recent experimental realization of Majorana modes by several groups provides an important scientific opportunity to explore these intriguing quasiparticles and provides a possible pathway to realize more general anyonic systems. Advances in 2D materials, including topological surface states, new measurement capabilities, and recent theoretical progress in analyzing strongly correlated systems are rapidly advancing us toward additional breakthroughs. In solid state experiments, for example, inducing superconductivity into quantum Hall edge states or other topological states may provide for more robust platforms. Further, as graphene/hexagonal boron nitride films have enabled extraordinarily high quality materials, material initiatives of this nature may resolve many troublesome interface effects. In atomic and molecular physics several concurrent advances such as single-site addressability, Feshbach molecules in optical lattices, and synthetic fields have led to several possible experimental pathways for the realization and study of anyons in these systems as well. Specific experimental approaches are now possible, informed by recent advances in theory of topological states, which may enable new platforms to bypass the fragility of the FQHE states. Timing is critical to make a concerted advancement to explore this previously inaccessible landscape. 

Objective: The purpose of this MURI is to unambiguously realize new systems exhibiting the physics of anyons and to verify their topological protection against decoherence. 

Research Concentration Areas: Approaches to create, verify and study emergent topological order with fractional quantum statistics include but are not limited to: (1) molecular gases trapped in optical lattices that may give rise to emergent anyons and their characterization, (2) demonstrate the evidence of anyons in low dimensional materials or heterostructures , (3) advanced theory development for Andreev and quantum Hall physics in topological superconducting states, including both molecular gas and solid state systems, (4) experimental investigation of topological protection of anyonic quasiparticles, and (5) characterization of interfaces to determine the connection between superconductivity and topological states. A cross-disciplinary effort in which molecular gas and solid state implementations are informing the separate approaches is a critical element of this MURI. 

Anticipated Resources: It is anticipated that awards under this topic will be no more than an average of $1.25M per year for 5 years, supporting no more than 6 funded faculty researchers. Exceptions warranted by specific proposal approaches should be discussed with the topic chief during the white paper phase of the solicitation. 

Research Topic Chiefs:

Dr. Paul Baker, 919-549-4202, paul.m.baker4.civ@mail.mil

Dr. Marc Ulrich 919-549-4319, marc.d.ulrich.civ@mail.mil

Dr. Pani Varanasi 919-549-4325, Chakrapani.v.varanasi.civ@mail.mil