This book offers a concise introduction to non-Fermi liquid (NFL) statesmetallic systems that lie beyond the scope of Landau Fermi liquid theory. NFLs emerge in strongly interacting quantum many-body systems, where conventional quasiparticle descriptions fail due to coupling between soft Fermi surface fluctuations and gapless bosonic modes. These systems are governed by strongly coupled quantum field theories and are often linked to anomalous transport behavior in unconventional superconductors.

The text presents analytic techniques, including dimensional regularization, for studying NFLs in a controlled framework. Topics include the Ising-nematic quantum critical point, superconducting instabilities enhanced by Ising-nematic fluctuations, NFL behaviour induced by transverse gauge fields, and the NFL induced by charge-density wave orderings. A basic background in quantum field theory is assumed.

This volume is intended for graduate students and researchers in theoretical condensed matter physics, particularly those working on quantum criticality and emergent metallic phases.

Provides a concise and accessible introduction to non-Fermi liquid (NFL) states Introduces core quantum field theory techniques relevant to strongly correlated electron systems Bridges the gap between advanced textbooks and current research literature on non-Fermi liquids

Autorentext

Prof. Dr. Ipsita Mandal is an internationally recognized expert in quantum condensed matter theory. She earned her PhD from the Harish-Chandra Research Institute in 2011 and has held research positions at institutions including UCLA, Perimeter Institute, University of Basel, MPI-PKS, and Cornell University. In 2017, she joined IIT Kharagpur as an Assistant Professor and was appointed Associate Professor at the University of Stavanger in 2019. She moved to the Polish Academy of Sciences in 2020, where she received the Polish Prime Minister's Award for Outstanding Scientific Achievements based on her Habilitation Thesis.

Since 2023, she has been affiliated with the Shiv Nadar Institute of Eminence (India) and was awarded a Marie Skodowska-Curie FRIAS COFUND Fellowship at the W3 professorial level. According to Stanford/Elsevier rankings, she was among the top 2% most cited scientists in 2024 and 2025. She has been honored under Springer Nature's Her Research, Our Future campaign for her contributions to research and sustainability. Her accolades include the Nordita Corresponding Fellowship, Ramanujan Fellowship, ICTP Associate Fellowship, Senior Dresden Fellowship, and the CAS President's International Fellowship. Her research focuses on strongly correlated quantum materials, with expertise in quantum field theory techniques applied to solid-state systems.

Inhalt

Introduction Non Fermi liquids.- Ising Nematic Quantum Critical Point.- Superconducting Instability Enhanced By Ising Nematic Order Parameter.- NFL arising from a critical Fermi surface interacting with transverse gauge fields.- NFL to FL crossover in states with valley polarized nematic ordering.