Publications (44)
High Temperature Superconductivity in the Cuprates: Materials, Phenomena and a Mechanism
Sumilan Banerjee, Chandan Dasgupta, Subroto Mukerjee +2
Superconductivity in the cuprates, discovered in the late 1980s and occurring at unprecedentedly high temperatures (up to about 140K) in about thirty chemically distinct families,…
Pairing Fluctuations Determine Low Energy Electronic Spectra in Cuprate Superconductors
Sumilan Banerjee, T V Ramakrishnan, C Dasgupta
We describe here a minimal theory of tight binding electrons moving on the square planar Cu lattice of the hole-doped cuprates and mixed quantum mechanically with pairs of them (Co…
Variable-range hopping through marginally localized phonons
Sumilan Banerjee, Ehud Altman
We investigate the effect of coupling Anderson localized particles in one dimension to a system of marginally localized phonons having a symmetry protected delocalized mode at zero…
Generation of Volume-Law Entanglement by Local-Measurement-Only Quantum Dynamics
Surajit Bera, Igor V. Gornyi, Sumilan Banerjee +1
Repeated local measurements typically have adversarial effects on entangling unitary dynamics, as local measurements usually degrade entanglement. However, recent works on measurem…
Quantized conductance with non-zero shot noise as a signature of Andreev edge state
Manas Ranjan Sahu, Arup Kumar Paul, Jagannath Sutradhar +6
Electrical conductance measurements have limited scope in identifying Andreev edge states (AESs), which form the basis for realizing various topological excitations in quantum Hall…
On the stability of many-body localization in
Ionut-Dragos Potirniche, Sumilan Banerjee, Ehud Altman
Recent work by De Roeck et al. [Phys. Rev. B 95, 155129 (2017)] has argued that many-body localization (MBL) is unstable in two and higher dimensions due to a thermalization avalan…
Tunable Chaos in the Finite Mean SYK Model
Arkaprava Mukherjee, Sumilan Banerjee, Sandip P. Trivedi +1
The complex Sachdev-Ye-Kitaev (SYK) model, featuring fermions with all-to-all interactions, serves as a dual paradigm for understanding non-Fermi liquid behavior and the holographi…
Localization physics in graphene Moire superlattices
Chandan Kumar, Saurabh Kumar Srivastav, Priyo Adhikary +3
Non-trivial Berry phase of graphene leads to unusual quantum correction to the conductivity. Berry phase of pi in single layer graphene (SLG) and 2pi in bi-layer graphene (BLG) is…
Schwinger-Keldysh field theory for operator Rényi entropy and entanglement growth in non-interacting systems with sub-ballistic transports
Priesh Roy, Sumilan Banerjee
The notion of operator growth in quantum systems furnishes a bridge between transport and the generation of entanglement between different parts of the system under quantum dynamic…
Quantum to classical crossover in many-body chaos and scrambling from relaxation in a glass
Surajit Bera, K. Y. Venkata Lokesh, Sumilan Banerjee
Chaotic quantum systems with Lyapunov exponent obey an upper bound at temperature , implying a divergence of the bound…
Dynamical mean-field theory for Rényi entanglement entropy and mutual Information in Hubbard Model
Surajit Bera, Arijit Haldar, Sumilan Banerjee
Quantum entanglement, lacking any classical counterpart, provides a fundamental new route to characterize the quantum nature of many-body states. In this work, we discuss an implem…
Ferromagnetic exchange, spin-orbit coupling and spiral magnetism at the LaAlO_3/SrTiO_3 interface
Sumilan Banerjee, Onur Erten, Mohit Randeria
The electronic properties of the polar interface between insulating oxides is a subject of great current interest. An exciting new development is the observation of robust magnetis…
Renyi entanglement entropy of Fermi liquids and non-Fermi liquids: Sachdev-Ye-Kitaev model and dynamical mean field theories
Arijit Haldar, Surajit Bera, Sumilan Banerjee
We present a new method for calculating Renyi entanglement entropies for fermionic field-theories originating from microscopic Hamiltonians. The method builds on an operator identi…
Enhanced Stability of Skyrmions in Two-Dimensional Chiral Magnets with Rashba Spin-Orbit Coupling
Sumilan Banerjee, James Rowland, Onur Erten +1
Recent developments have led to an explosion of activity on skyrmions in three-dimensional (3D) chiral magnets. Experiments have directly probed these topological spin textures, re…
Many-body chaos and anomalous diffusion across thermal phase transitions in two dimensions
Sibaram Ruidas, Sumilan Banerjee
Chaos is an important characterization of classical dynamical systems. How is chaos linked to the long-time dynamics of collective modes across phases and phase transitions? We add…
Thermopower probing emergent local moments in magic-angle twisted bilayer graphene
Ayan Ghosh, Souvik Chakraborty, Ranit Dutta +7
Recent experiments on magic-angle twisted bilayer graphene (MATBLG) have revealed the formation of flatbands, suggesting that correlation effects are likely to dominate in this sys…
Doping dependence of fluctuation diamagnetism in High Tc superconductors
Kingshuk Sarkar, Sumilan Banerjee, Subroto Mukerjee +1
Using a recently proposed Ginzburg-Landau-like lattice free energy functional due to Banerjee et al. Phys. Rev. B 83, 024510 (2011) we calculate the fluctuation diamagnetism of hig…
Quantum fluctuations lead to glassy electron dynamics in the good metal regime of electron doped KTaO3
Shashank Kumar Ojha, Sankalpa Hazra, Surajit Bera +10
One of the central challenges in condensed matter physics is to comprehend systems that have strong disorder and strong interactions. In the strongly localized regime, their subtle…
Quench, thermalization and residual entropy across a non-Fermi liquid to Fermi liquid transition
Arijit Haldar, Prosenjit Haldar, Surajit Bera +2
We study the thermalization, after sudden and slow quenches, of an interacting model having a quantum phase transition from a Sachdev-Ye-Kitaev (SYK) non-Fermi liquid (NFL) to a Fe…
Skyrmions in Chiral Magnets with Rashba and Dresselhaus Spin-Orbit Coupling
James Rowland, Sumilan Banerjee, Mohit Randeria
Skyrmions are topological spin textures of interest for fundamental science and applications. Previous theoretical studies have focused on systems with broken bulk inversion symmet…
Semiclassical Limit of Measurement-Induced Transition in Many-Body Chaos in Integrable and Nonintegrable Oscillator Chains
Sibaram Ruidas, Sumilan Banerjee
We discuss the dynamics of integrable and nonintegrable chains of coupled oscillators under continuous weak position measurements in the semiclassical limit. We show that, in this…
Electronic Structure of Oxide Interfaces: A Comparative Analysis of GdTiO/SrTiO and LaAlO/SrTiO Interfaces
Hrishit Banerjee, Sumilan Banerjee, Mohit Randeria +1
Emergent phases in the two-dimensional electron gas (2DEG) formed at the interface between two insulating oxides have attracted great attention in the past decade. We present ab-in…
Entanglement entropy of fermions in a strange metal
Santanu Singh, Surajit Bera, Chenyuan Li +2
The subsystem-size dependence of ground-state entanglement entropy and its crossover to thermal entropy as a function of temperature are well understood for one-dimensional (1D) ga…
Universal quantized thermal conductance in graphene
Saurabh Kumar Srivastav, Manas Ranjan Sahu, K. Watanabe +3
The universal quantization of thermal conductance provides information on the topological order of a state beyond electrical conductance. Such measurements have become possible onl…
Phenomenological Ginzburg-Landau-like theory for superconductivity in the cuprates
Sumilan Banerjee, T. V. Ramakrishnan, Chandan Dasgupta
We propose a phenomenological Ginzburg-Landau-like theory of cuprate superconductivity. The free energy is expressed as a functional F of the spin-singlet pair amplitude psi_ij=psi…
Inverse Superconductor-Insulator Transition in Weakly Monitored Josephson Junction Arrays
Purnendu Das, Sumilan Banerjee
Control and manipulation of quantum states by measurements and bath engineering in open quantum systems have emerged as new paradigms in many-body physics. Here, taking a prototypi…
Information scrambling and butterfly velocity in quantum spin glass chains
Venkata Lokesh K. Y, Surajit Bera, Sumilan Banerjee
We make lattice generalization of two well-known zero-dimensional models of quantum spin glass, Sachdev-Ye (SY) and spherical quantum -spin glass model, to one dimension for stu…
Interaction driven giant thermopower in magic-angle twisted bilayer graphene
Arup Kumar Paul, Ayan Ghosh, Souvik Chakraborty +9
Magic-angle twisted bilayer graphene (MtBLG) has proven to be an extremely promising new platform to realize and study a host of emergent quantum phases arising from the strong cor…
Scaling of Fock-space propagator and multifractality across the many-body localization transition
Jagannath Sutradhar, Soumi Ghosh, Sthitadhi Roy +3
We implement a recursive Green function method to extract the Fock space (FS) propagator and associated self-energy across the many-body localization (MBL) transition, for one-dime…
Many-body critical phase in a quasiperiodic chain and dynamical Widom lines in Fock space properties
Nilanjan Roy, Subroto Mukerjee, Sumilan Banerjee
We study a quasiperiodic model in one dimension, namely the extended Aubry-André-Harper (EAAH) chain, that realizes a critical phase comprising entirely single-particle critical s…
Characterization of the Dynamics of Glass-forming Liquids from the Properties of the Potential Energy Landscape
Sumilan Banerjee, Chandan Dasgupta
We develop a framework for understanding the difference between strong and fragile behavior in the dynamics of glass-forming liquids from the properties of the potential energy lan…
Diagnostics of nonergodic extended states and many body localization proximity effect through real-space and Fock-space excitations
Nilanjan Roy, Jagannath Sutradhar, Sumilan Banerjee
We provide real-space and Fock-space (FS) characterizations of ergodic, nonergodic extended (NEE) and many-body localized (MBL) phases in an interacting quasiperiodic system, namel…
Entanglement in non-equilibrium steady states and many-body localization breakdown in a current driven system
Animesh Panda, Sumilan Banerjee
We model a one-dimensional (1D) current-driven interacting disordered system through a non-Hermitian Hamiltonian with asymmetric hopping and study the entanglement properties of it…
The correlation between the Nernst effect and fluctuation diamagnetism in strongly fluctuating superconductors
Kingshuk Sarkar, Sumilan Banerjee, Subroto Mukerjee +1
We study the Nernst effect in fluctuating superconductors by calculating the transport coefficient in a phenomenological model where relative importance of phase and ampl…
Excess entropy and breakdown of semiclassical description of thermoelectricity in twisted bilayer graphene close to half filling
Bhaskar Ghawri, Phanibhusan S. Mahapatra, Shinjan Mandal +9
In moiré systems with twisted bilayer graphene (tBLG), the amplification of Coulomb correlation effects at low twist angles () is a result of nearly flat low-energy electronic…
Scaling of Fock space propagator in quasiperiodic many-body localizing systems
Soumi Ghosh, Jagannath Sutradhar, Subroto Mukerjee +1
Recently many body localized systems have been treated as a hopping problem on a Fock space lattice with correlated disorder, where the many-body eigenstates exhibit multi-fractal…
Solvable model for a dynamical quantum phase transition from fast to slow scrambling
Sumilan Banerjee, Ehud Altman
We propose an extension of the Sachdev-Ye-Kitaev (SYK) model that exhibits a quantum phase transition from the previously identified non-Fermi liquid fixed point to a Fermi liquid…
Higher-dimensional SYK Non-Fermi Liquids at Lifshitz transitions
Arijit Haldar, Sumilan Banerjee, Vijay B. Shenoy
We address the key open problem of a higher dimensional generalization of the Sachdev-Ye-Kitaev (SYK) model. We construct a model on a lattice of SYK dots with non-random intersite…
Transport, multifractality, and the breakdown of single-parameter scaling at the localization transition in quasiperiodic systems
Jagannath Sutradhar, Subroto Mukerjee, Rahul Pandit +1
There has been a revival of interest in localization phenomena in quasiperiodic systems with a view to examining how they differ fundamentally from such phenomena in random systems…
Emergent nanoscale superparamagnetism at oxide interfaces
Yonathan Anahory, Lior Embon, Chang Jian Li +12
Atomically sharp oxide heterostructures exhibit a range of novel physical phenomena that do not occur in the parent bulk compounds. The most prominent example is the appearance of…
Quantum Oscillations in the Magnetisation and Density of States of Insulators
Animesh Panda, Sumilan Banerjee, Mohit Randeria
The observation of -periodic behavior in Kondo insulators SmB and YbB challenges the conventional wisdom that quantum oscillations (QO) necessarily arise from Fermi…
Electric field tunable superconductivity with competing orders in twisted bilayer graphene near magic-angle
Ranit Dutta, Ayan Ghosh, Shinjan Mandal +6
Superconductivity (SC) in twisted bilayer graphene (tBLG) has been explored by varying carrier concentrations, twist angles, and screening strength, with the aim of uncovering its…
Universal non-equilibrium dynamics of pure states and density-dependent thermalization in Sachdev-Ye-Kitaev model
Rishik Perugu, Arijit Haldar, Sumilan Banerjee
Non-equilibrium dynamics of unentangled and entangled pure states in interacting quantum systems is crucial for harnessing quantum information and to understand quantum thermalizat…
Quantum oscillations in a d-wave vortex liquid
Sumilan Banerjee, Shizhong Zhang, Mohit Randeria
The observation of quantum oscillations in underdoped cuprates has generated intense debate about the nature of the field-induced resistive state and its implications for the `norm…