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Emergent Exotic Phases of Matter
Condensed matter physics is the physics of solids and liquids (condensed phases of matter). It is the study of the complex behaviour of a large number of interacting particles such that their collective behaviour gives rise to emergent properties. In this talk, I will discuss some interesting quantum condensed matter systems with their intriguing emergent phenomena arising from complexity. We will revisit the Landau paradigm of Fermi liquid theory, and thereby understand the properties of the non-Fermi liquid systems which cannot be described within the Landau framework, due to the destruction of the Landau quasiparticles. In particular, we will focus on critical Fermi surface states, where there is a well-defined Fermi surface, but no quasiparticles, as a result of the strong interactions between the Fermi surface and some massless boson(s). We will outline a framework to extract the low-energy physics of such systems in a controlled approximation, using the tool of dimensional regularization.
In the second part of my talk, I will also outline my future directions of research, which I think will be fruitful in the coming few years. This involves studying emergent non-Fermi liquid states in highly tunable and simpler (experimentally) systems like twisted bilayer graphene, and tractable (theoretically) "artificial" systems like the Sachdev-Ye-Kitaev like models.
References :
1) Ultraviolet/infrared mixing in Non-Fermi Liquids
Ipsita Mandal and Sung-Sik Lee
Phys. Rev. B 92, 035141 (2015)
2) Superconducting instability in non-Fermi liquids
Ipsita Mandal
Phys. Rev. B 94, 115138 (2016)
3) Hyperscaling violation at the Ising-nematic quantum critical point in two dimensional metals
Andreas Eberlein, Ipsita Mandal and Subir Sachdev
Phys. Rev. B 94, 045133 (2016)
4) Non-Fermi liquid at the FFLO quantum critical point
Dimitri Pimenov, Ipsita Mandal, Francesco Piazza and Matthias Punk
Phys. Rev. B 98, 024510 (2018)
e-Print : arXiv:1711.10514 [cond-mat.str-el]
5) Critical Fermi surfaces in generic dimensions arising from transverse gauge field interactions
Ipsita Mandal
e-Print : arXiv:2006.10766 [cond-mat.str-el]
6) Correlated Insulators in Twisted Bilayer Graphene
Ipsita Mandal, Jia Yao, and Erich J. Mueller
e-Print : arXiv:2008.13752 [cond-mat.str-el]