CAREER: QFT & beyond: new structures and tools for compressible phases

NONTECHNICAL SUMMARY

This award funds research and education into the study of novel materials, where strong interactions between particles give rise to unique and complex behaviors that challenge traditional understanding. Metals are a cornerstone of condensed matter physics and materials science, with wide-ranging applications; their efficient conduction of electricity and heat arises from quantum mechanical laws that create a coordinated, collective motion among particles.

However, current theories struggle to explain what happens when particles within these metals interact strongly. Such strongly interacting metals are known to exhibit certain remarkable properties, including high-temperature superconductivity. Yet, the diversity of these phases and their possible behaviors remains unexplored, largely due to a lack of suitable theoretical tools, placing them at the forefront of challenges in theoretical physics.

This research will develop new theoretical tools to better understand and predict these unusual states of matter. By building on the latest advances in quantum field theory, it will provide new ways to explore how the structure of these materials affects their behavior. A key focus will be on understanding the unique patterns of correlation that can arise in metals, especially in strongly interacting phases.

Some of these correlations involve quantum entanglement, a fundamental property that links particles in ways that classical physics cannot describe. Metals are among the most entangled states known, and understanding this entanglement is crucial, as it serves as a valuable resource for advancing quantum materials and quantum information science. This work will also shed light on fundamental quantum limits to how quickly these systems can reach thermal equilibrium, providing a deeper grasp of quantum mechanics.

Ultimately, the insights gained may expand our understanding of the quantum world and open new avenues in the study of exotic phases of matter.

The educational aspect of the project focuses on expanding access to education on modern quantum physics. Through the "TeachQuantum" program, high school teachers, especially from underserved communities in Chicago's South Side, will engage in quantum research experiences and bring these concepts to their classrooms, inspiring the next generation of scientists.

Additionally, the project will revamp university-level courses to make quantum field theory more accessible to a broader audience. These efforts aim to cultivate a diverse and scientifically literate workforce. TECHNICAL SUMMARY

The integration of Quantum Field Theory (QFT) into condensed matter physics has profoundly expanded our understanding of material phases and their underlying mechanisms. However, despite significant progress, critical challenges remain, particularly in the experimentally relevant context of compressible phases of matter, such as Fermi liquids and non-Fermi liquids.

The combination of extreme gaplessness and strong correlation makes the dynamics of non-Fermi liquids one of the most challenging problems in condensed matter physics, and constitutes a true frontier in QFT research.

This research builds on recent developments in QFT to construct innovative approaches that can handle the extreme gaplessness of Fermi surfaces. It will exploit and refine generalized symmetries and their anomalies to identify the appropriate structure that underpins the nonlinear dynamics of Fermi liquids. It will also leverage recently discovered effective field theories (EFT) for Fermi liquids to establish controlled perturbative and non-perturbative approaches to non-Fermi liquids.

One key objective is to understand protected geometric observables in Fermi liquids, and extend these insights to non-Fermi liquids. The proposed research will make use of UV/IR constraints to study these phases and their dynamics, with another goal being to prove the Planckian thermalization bound, a conjectured fundamental limit on how quickly systems can thermalize.

It will furthermore investigate thermalization through the lens of quantum information and effective field theory, aiming to propose novel applications of quantum technologies.

The educational aspect of the project focuses on expanding access to education on modern quantum physics. Through the "TeachQuantum" program, high school teachers, especially from underserved communities in Chicago's South Side, will engage in quantum research experiences and bring these concepts to their classrooms, inspiring the next generation of scientists.

Additionally, the project will revamp university-level courses to make quantum field theory more accessible to a broader audience. These efforts aim to cultivate a diverse and scientifically literate workforce.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.