papers

Publications (196)

cond-mat.mes-hall2017

Effects of local periodic driving on transport and generation of bound states

Adhip Agarwala, Diptiman Sen

We periodically kick a local region in a one-dimensional lattice and demonstrate, by studying wave packet dynamics, that the strength and the time period of the kicking can be used…

cond-mat.mtrl-sci2016

Granular topological insulators

Abhishek Banerjee, Oindrila Deb, Kunjalata Majhi +3

Granular conductors form an artificially engineered class of solid state materials wherein the microstructure can be tuned to mimic a wide range of otherwise inaccessible physical…

cond-mat.mes-hall2006

Non-equilibrium Green's function formalism and the problem of bound states

Abhishek Dhar, Diptiman Sen

The non-equilibrium Green's function formalism for infinitely extended reservoirs coupled to a finite system can be derived by solving the equations of motion for a tight-binding H…

cond-mat.stat-mech2024

Dynamical localization and slow thermalization in a class of disorder-free periodically driven one-dimensional interacting systems

Sreemayee Aditya, Diptiman Sen

We study if the interplay between dynamical localization and interactions in periodically driven quantum systems can give rise to anomalous thermalization behavior. Specifically, w…

cond-mat.stat-mech1997

Applications of the Collective Field Theory for the Calogero-Sutherland Model

Diptiman Sen, R. K. Bhaduri

We use the collective field theory known for the Calogero-Sutherland model to study a variety of low-energy properties. These include the ground state energy in a confining potenti…

quant-ph2015

Detection of a quantum particle on a lattice under repeated projective measurements

Shrabanti Dhar, Subinay Dasgupta, Abhishek Dhar +1

We consider a quantum particle, moving on a lattice with a tight-binding Hamiltonian, which is subjected to measurements to detect it's arrival at a particular chosen set of sites.…

cond-mat.stat-mech2015

Maximum group velocity in a one-dimensional model with a sinusoidally varying staggered potential

Tanay Nag, Diptiman Sen, Amit Dutta

We use Floquet theory to study the maximum value of the stroboscopic group velocity in a one-dimensional tight-binding model subjected to an on-site staggered potential varying sin…

cond-mat.mes-hall2015

Majorana modes and transport across junctions of superconductors and normal metals

Manisha Thakurathi, Oindrila Deb, Diptiman Sen

We study Majorana modes and transport in one-dimensional systems with a -wave superconductor (SC) and normal metal leads. For a system with a SC lying between two leads, it is k…

cond-mat.stat-mech2021

Dynamical relaxation of correlators in periodically driven integrable quantum systems

Sreemayee Aditya, Sutapa Samanta, Arnab Sen +2

We show that the correlation functions of a class of periodically driven integrable closed quantum systems approach their steady state value as , where is the n…

cond-mat.str-el2011

Quenching across quantum critical points in periodic systems: dependence of scaling laws on periodicity

Manisha Thakurathi, Wade DeGottardi, Diptiman Sen +1

We study the quenching dynamics of a many-body system in one dimension described by a Hamiltonian that has spatial periodicity. Specifically, we consider a spin-1/2 chain with equa…

cond-mat1993

Bosonic Mean Field Theory of the Spiral Phases of Heisenberg Antiferromagnets on a Chain

Sumathi Rao, Diptiman Sen

We develop a novel bosonic mean field theory to describe the spiral phases of a Heisenberg antiferromagnet on a one-dimensional chain, in terms of three bosons at each site. The gr…

cond-mat.stat-mech2026

Floquet scars and prethermal fragmentation in a driven spin-one chain

Krishanu Ghosh, Diptiman Sen, K. Sengupta

We study the periodic dynamics of a spin-one chain driven using a square-pulse protocol with amplitude and frequency . The Hamiltonian of the spin chain hosts a thermod…

cond-mat.mes-hall2016

Transport across a system with three p-wave superconducting wires: effects of Majorana modes and interactions

Oindrila Deb, Manisha Thakurathi, Diptiman Sen

We study the effects of Majorana modes and interactions between electrons on transport in a one-dimensional system with a junction of three p-wave superconductors (SCs) which are c…

cond-mat.mes-hall2026

Su-Schrieffer-Heeger model driven by sequences of two unitaries: periodic, quasiperiodic, aperiodic, and random protocols

Maitri Ganguli, Diptiman Sen

We study the effect of driving the Su-Schrieffer-Heeger model using two unitary operators and in different combinations; the unitaries differ in the values of the inter…

cond-mat.mes-hall2013

Floquet generation of Majorana end modes and topological invariants

Manisha Thakurathi, Aavishkar A. Patel, Diptiman Sen +1

We show how Majorana end modes can be generated in a one-dimensional system by varying some of the parameters in the Hamiltonian periodically in time. The specific model we conside…

cond-mat.mes-hall2007

Correlators and fractional statistics in the quantum Hall bulk

Smitha Vishveshwara, Michael Stone, Diptiman Sen

We derive single-particle and two-particle correlators of anyons in the presence of a magnetic field in the lowest Landau level. We show that the two-particle correlator exhibits s…

cond-mat.mes-hall2000

Magnetization of Mn_12 Ac in a slowly varying magnetic field: an ab initio study

Indranil Rudra, S. Ramasesha, Diptiman Sen

Beginning with a Heisenberg spin Hamiltonian for the manganese ions in the Mn_12 Ac molecule, we find a number of low-energy states of the system. We use these states to solve the…

cond-mat.stat-mech2019

Fibonacci steady states in a driven integrable quantum system

Somnath Maity, Utso Bhattacharya, Amit Dutta +1

We study an integrable system that is reducible to free fermions by a Jordan-Wigner transformation which is subjected to a Fibonacci driving protocol based on two non-commuting Ham…

cond-mat.stat-mech2012

Fidelity susceptibility of one-dimensional models with twisted boundary conditions

Manisha Thakurathi, Diptiman Sen, Amit Dutta

Recently it has been shown that the fidelity of the ground state of a quantum many-body system can be used to detect its quantum critical points (QCPs). If g denotes the parameter…

cond-mat.stat-mech2008

Exact results for quench dynamics and defect production in a two-dimensional model

K. Sengupta, Diptiman Sen, Shreyoshi Mondal

We show that for a d-dimensional model in which a quench with a rate τ^{-1} takes the system across a d-m dimensional critical surface, the defect density scales as n \sim 1/τ^{m…

hep-th1993

Semiclassical analysis of two- and three-spin antiferromagnets and anyons on a sphere

Diptiman Sen

We do a semiclassical analysis for two or three spins which are coupled antiferromagnetically to each other. The semiclassical wave functions transform correctly under permutations…

cond-mat.str-el2019

Effective theories for quantum spin clusters: Geometric phases and state selection by singularity

Subhankar Khatua, Diptiman Sen, R. Ganesh

Magnetic systems with frustration often have large classical degeneracy. We show that their low-energy physics can be understood as dynamics within the space of classical ground st…

cond-mat.stat-mech2023

Effects of topological and non-topological edge states on information propagation and scrambling in a Floquet spin chain

Samudra Sur, Diptiman Sen

The action of any local operator on a quantum system propagates through the system carrying the information of the operator. This is usually studied via the out-of-time-order corre…

cond-mat.mes-hall2019

Transport on a topological insulator surface with a time-dependent magnetic barrier

Adithi Udupa, K. Sengupta, Diptiman Sen

We study transport across a time-dependent magnetic barrier present on the surface of a three-dimensional topological insulator. We show that such a barrier can be implemented for…

cond-mat.str-el2004

Coulomb gap in one-dimensional disordered electronic systems

Amit Dutta, Lars Fritz, Diptiman Sen

We study a one-dimensional system of spinless electrons in the presence of a long-range Coulomb interaction (LRCI) and a random chemical potential at each site. We first present a…

cond-mat.str-el2008

A Theoretical Approach for Computing Magnetic Anisotropy in Single Molecule Magnets

Rajamani Raghunathan, S. Ramasesha, Diptiman Sen

We present a theoretical approach to calculate the molecular magnetic anisotropy parameters, and for single molecule magnets in any eigenstate of the exchange Hamiltoni…

cond-mat.mes-hall2017

Electron dynamics in graphene with spin-orbit couplings and periodic potentials

Ranjani Seshadri, Diptiman Sen

We use both continuum and lattice models to study the energy-momentum dispersion and the dynamics of a wave packet for an electron moving in graphene in the presence of spin-orbit…

cond-mat.stat-mech2004

Magnetic properties of a helical spin chain with alternating isotropic and anisotropic spins: magnetization plateaus and finite entropy

V. Ravi Chandra, S. Ramasesha, Diptiman Sen

We study a model which could explain some of the unusual magnetic properties observed for the one-dimensional helical spin system Co(hfac)_2 NITPhOMe. One of the properties observe…

quant-ph2025

Heating suppression via two-rate random and quasiperiodic drive protocols

Krishanu Ghosh, Sayan Choudhury, Diptiman Sen +1

We study a random and quasiperiodically driven one-dimensional non-integrable PXP spin chain in a magnetic field for two distinct drive protocols. Each of these protocols involves…

cond-mat.mes-hall2009

Nonequilibrium charge transport in an interacting open system: two-particle resonance and current asymmetry

Dibyendu Roy, Abhiram Soori, Diptiman Sen +1

We use Lippman-Schwinger scattering theory to study nonequilibrium electron transport through an interacting open quantum dot. The two-particle current is evaluated exactly while w…

cond-mat1995

Phase Diagram of the Spin-One Heisenberg System with Dimerization and Frustration

Swapan Pati, R. Chitra, Diptiman Sen +2

We use the density matrix renormalization group method to study the ground state properties of an antiferromagnetic spin- chain with a next-nearest neighbor exchange and…

cond-mat.mes-hall2010

Power dissipation for systems with junctions of multiple quantum wires

Amit Agarwal, Sourin Das, Diptiman Sen

We study power dissipation for systems of multiple quantum wires meeting at a junction, in terms of a current splitting matrix (M) describing the junction. We present a unified fra…

cond-mat.str-el2001

Exact and Approximate Theoretical Techniques for Quantum Magnetism in Low Dimensions

Swapan K. Pati, S. Ramasesha, Diptiman Sen

Quantum magnetism in low dimensions has been one of the central areas of theoretical research for many decades now. One of the key reasons for the long standing interest in this fi…

physics.optics2025

Probing the Topological Anderson Transition in Quasiperiodic Photonic Lattices via Chiral Displacement and Wavelength Tuning

Abhinav Sinha, Trideb Shit, Avinash Tetarwal +2

The interplay of topology and disorder in quantum dynamics has recently attracted significant attention across diverse platforms, including solid-state devices, ultracold atoms, an…

cond-mat.stat-mech2014

Dynamical localization in a chain of hard core bosons under a periodic driving

Tanay Nag, Sthitadhi Roy, Amit Dutta +1

We study the dynamics of a one-dimensional lattice model of hard core bosons which is initially in a superfluid phase with a current being induced by applying a twist at the bounda…

cond-mat.str-el2010

Modified DMRG algorithm for the zigzag spin-1/2 chain with frustrated antiferromagnetic exchange: Comparison with field theory at large

Manoranjan Kumar, Zoltan G. Soos, Diptiman Sen +1

A modified density matrix renormalization group (DMRG) algorithm is applied to the zigzag spin-1/2 chain with frustrated antiferromagnetic exchange , between first and s…

cond-mat.stat-mech2012

Quantum fidelity for one-dimensional Dirac fermions and two-dimensional Kitaev model in the thermodynamic limit

Victor Mukherjee, Amit Dutta, Diptiman Sen

We study the scaling behavior of the fidelity () in the thermodynamic limit using the examples of a system of Dirac fermions in one dimension and the Kitaev model on a honeycomb…

cond-mat.str-el2001

Field Theoretic Studies of Quantum Spin Systems in One Dimension

Diptiman Sen

We describe some field theoretic methods for studying quantum spin systems in one dimension. These include the nonlinear sigma-model approach which is particularly useful for large…

cond-mat.stat-mech2010

Quenching across quantum critical points: role of topological patterns

Diptiman Sen, Smitha Vishveshwara

We introduce a one-dimensional version of the Kitaev model consisting of spins on a two-legged ladder and characterized by Z_2 invariants on the plaquettes of the ladder. We map th…

cond-mat.str-el2019

Transport across junctions of pseudospin-one fermions

Sourav Nandy, K. Sengupta, Diptiman Sen

We study transport across ballistic junctions of materials which host pseudospin-one fermions as emergent low-energy quasiparticles. The effective low-energy Hamiltonians of such f…

cond-mat.mes-hall2016

Edge states, spin transport and impurity induced local density of states in spin-orbit coupled graphene

Ranjani Seshadri, K. Sengupta, Diptiman Sen

We study graphene which has both spin-orbit coupling (SOC), taken to be of the Kane-Mele form, and a Zeeman field induced due to proximity to a ferromagnetic material. We show that…

cond-mat.str-el2007

Spin-1 chain with spin-1/2 excitations in the bulk

Diptiman Sen, Naveen Surendran

We present a spin-1 chain with a Hamiltonian which has three exactly solvable ground states. Two of these are fully dimerized, analogous to the Majumdar-Ghosh (MG) states of a spin…

cond-mat.stat-mech2007

Quenching Dynamics of a quantum XY spin-1/2 chain in presence of a transverse field

Victor Mukherjee, Uma Divakaran, Amit Dutta +1

We study the quantum dynamics of a one-dimensional spin-1/2 anisotropic XY model in a transverse field when the transverse field or the anisotropic interaction is quenched at a slo…

cond-mat1996

Semiclassical and field theoretic studies of Heisenberg antiferromagnetic chains with frustration and dimerization

Sumathi Rao, Diptiman Sen

The Heisenberg antiferromagnetic spin chain with both dimerization and frustration is studied. The classical ground state has three phases (a Neel phase, a spiral phase and a colin…

cond-mat.str-el2020

Restoring coherence via aperiodic drives in a many-body quantum system

Bhaskar Mukherjee, Arnab Sen, Diptiman Sen +1

We study the unitary dynamics of randomly or quasi-periodically driven tilted Bose-Hubbard (tBH) model in one dimension deep inside its Mott phase starting from a sy…

cond-mat.mes-hall2007

Equation of motion approach to non-adiabatic quantum charge pumping

Amit Agarwal, Diptiman Sen

We use the equations of motion of non-interacting electrons in a one-dimensional system to numerically study different aspects of charge pumping. We study the effects of the pumpin…

cond-mat.mes-hall2008

Scattering of electrons from an interacting region

Abhishek Dhar, Diptiman Sen, Dibyendu Roy

We address the problem of transmission of electrons between two noninteracting leads through a region where they interact (quantum dot). We use a model of spinless electrons hoppin…

cond-mat.str-el2026

Second quantization of anyons and spin-anyon duality

Priyanshi Bhasin, Diptiman Sen, Tanmoy Das

Anyons exhibit a non-trivial interplay between local exclusion rules and non-local braiding and exchange phases, making a consistent commutation algebra and second-quantized formul…

cond-mat.mes-hall2025

Refraction Hall Effect

Ronika Sarkar, Arka Bandyopadhyay, Awadhesh Narayan +1

We introduce a new mechanism that produces a Hall-like response in time-reversal-invariant materials, driven entirely by geometric effects. Specifically, we demonstrate that a tilt…

quant-ph2025

Quantum dynamics of a spin model with an extensive degeneracy

Krishanu Ghosh, Diptiman Sen, K. Sengupta

We study the role played by extensive degeneracy in shaping the nature of the quantum dynamics of a one-dimensional spin model for both ramp and periodic drive protocols. The model…

cond-mat.stat-mech2014

Clusters of bound particles in a quantum integrable many-body system and number theory

B. Basu-Mallick, Tanaya Bhattacharyya, Diptiman Sen

We construct clusters of bound particles for a quantum integrable derivative delta-function Bose gas in one dimension. It is found that clusters of bound particles can be construct…

cond-mat.stat-mech2006

Infinite-range Ising ferromagnet in a time-dependent transverse field: quench and ac dynamics near the quantum critical point

Arnab Das, K. Sengupta, Diptiman Sen +1

We study an infinite range ferromagnetic Ising model in the presence of a transverse magnetic field which exhibits a quantum paramagnetic-ferromagnetic phase transition at a critic…

cond-mat.stat-mech1998

One-dimensional fermions with incommensurate hopping close to dimerization

Diptiman Sen, Siddhartha Lal

We study the spectrum of fermions hopping on a chain with a weak incommensuration close to dimerization; both q, the deviation of the wave number from pi, and delta, the strength o…

cond-mat.stat-mech2019

Dynamics of quasiperiodically driven spin systems

Sayak Ray, Subhasis Sinha, Diptiman Sen

We study the stroboscopic dynamics of a spin- object subjected to -function kicking in the transverse magnetic field which is generated following the Fibonacci sequence. The…

cond-mat1996

Novel correlations in two dimensions: Some exact solutions

M. V. N. Murthy, R. K. Bhaduri, Diptiman Sen

We construct a new many-body Hamiltonian with two- and three-body interactions in two space dimensions and obtain its exact many-body ground state for an arbitrary number of partic…

cond-mat.mes-hall2017

Generating surface states in a Weyl semi-metal by applying electromagnetic radiation

Oindrila Deb, Diptiman Sen

We show that the application of circularly polarized electromagnetic radiation on the surface of a Weyl semi-metal can generate states at that surface. These states can be characte…

cond-mat.str-el2003

Renormalization group study of the conductances of interacting quantum wire systems with different geometries

Sourin Das, Sumathi Rao, Diptiman Sen

We examine the effect of interactions between the electrons on the conductances of some systems of quantum wires with different geometries. The systems include a wire with a stub i…

cond-mat.str-el2001

Conductance through contact barriers of a finite length quantum wire

Siddhartha Lal, Sumathi Rao, Diptiman Sen

We use the technique of bosonization to understand a variety of recent experimental results on the conductivity of a quantum wire. The quantum wire is taken to be a finite-length L…

cond-mat1994

Thomas-Fermi Method For Particles Obeying Generalized Exclusion Statistics

Diptiman Sen, R. K. Bhaduri

We use the Thomas-Fermi method to examine the thermodynamics of particles obeying Haldane exclusion statistics. Specifically, we study Calogero-Sutherland particles placed in a giv…

cond-mat.str-el2020

Dynamics of the vacuum state in a periodically driven Rydberg chain

Bhaskar Mukherjee, Arnab Sen, Diptiman Sen +1

We study the dynamics of the periodically driven Rydberg chain starting from the state with zero Rydberg excitations (vacuum state denoted by ) using a square pulse prot…

cond-mat.str-el2002

Junction of several weakly interacting quantum wires: a renormalization group study

Siddhartha Lal, Sumathi Rao, Diptiman Sen

We study the conductance of three or more semi-infinite wires which meet at a junction. The electrons in the wires are taken to interact weakly with each other through a short-rang…

cond-mat.stat-mech2010

Spin-1 Kitaev model in one dimension

Diptiman Sen, R. Shankar, Deepak Dhar +1

We study a one-dimensional version of the Kitaev model on a ring of size N, in which there is a spin S > 1/2 on each site and the Hamiltonian is J \sum_i S^x_i S^y_{i+1}. The cases…

quant-ph2011

Exact Entanglement Studies of Strongly Correlated Systems: Role of Long-Range Interactions and Symmetries of the System

Shaon Sahoo, V. M. L. Durga Prasad Goli, S. Ramasesha +1

We study the bipartite entanglement of strongly correlated systems using exact diagonalization techniques. In particular, we examine how the entanglement changes in the presence of…

cond-mat.str-el2023

Detecting prethermal Floquet phases of Rydberg atom arrays

Somsubhra Ghosh, Diptiman Sen, K. Sengupta

We study the prethermal Floquet phases of a two-dimensional (2D) Rydberg atom array on a rectangular lattice in the presence of a periodic drive with large drive amplitude. We deri…

cond-mat.stat-mech2013

Clusters of bound particles in the derivative delta-function Bose gas

B. Basu-Mallick, Tanaya Bhattacharyya, Diptiman Sen

In this paper we discuss a novel procedure for constructing clusters of bound particles in the case of a quantum integrable derivative delta-function Bose gas in one dimension. It…

cond-mat.str-el1999

A Solvable Model of Interacting Fermions in Two Dimensions

B. Sriram Shastry, Diptiman Sen

We introduce and study an exactly solvable model of several species of fermions in which particles interact pairwise through a mutual magnetic field; the interaction operates only…

cond-mat.str-el2021

Bosonization study of a generalized statistics model with four Fermi points

Sreemayee Aditya, Diptiman Sen

We study a one-dimensional lattice model of fractional statistics in which particles have next-nearest-neighbor hopping between sites which depends on the occupation number at the…

cond-mat.mes-hall2002

Model Exact Low-Lying States and Spin Dynamics in Ferric Wheels; Fe to Fe

Indranil Rudra, S. Ramasesha, Diptiman Sen

Using an efficient numerical scheme that exploits spatial symmetries and spin-parity, we have obtained the exact low-lying eigenstates of exchange Hamiltonians for ferric wheels up…

cond-mat.str-el2012

Majorana Fermions in superconducting 1D systems having periodic, quasiperiodic, and disordered potentials

Wade DeGottardi, Diptiman Sen, Smitha Vishveshwara

We present a unified study of the effect of periodic, quasiperiodic and disordered potentials on topological phases that are characterized by Majorana end modes in 1D p-wave superc…

cond-mat1993

A Bosonic Mean-Field Theory for Frustrated Heisenberg Antiferromagnets in Two Dimensions

R. Chitra, Sumathi Rao, Diptiman Sen

We use a recently developed bosonic mean-field theory (MFT) to study the ordered ground states of frustrated Heisenberg antiferromagnets (FHAFM) in two dimensions. We emphasize the…

cond-mat.str-el2022

Driven Hubbard model on a triangular lattice: tunable Heisenberg antiferromagnet with three-spin chiral term

Samudra Sur, Adithi Udupa, Diptiman Sen

We study the effects of a periodically varying electric field on the Hubbard model at half-filling on a triangular lattice. The electric field is incorporated through the phase of…

cond-mat1996

A multispecies Calogero-Sutherland model

Diptiman Sen

Motivated by the concept of ideal mutual statistics, we study a multispecies Calogero-Sutherland model in which the interaction parameters and masses satisfy some specific relation…

cond-mat.stat-mech2021

Driven quantum many-body systems and out-of-equilibrium topology

Souvik Bandyopadhyay, Sourav Bhattacharjee, Diptiman Sen

In this review we present some of the work done in India in the area of driven and out-of-equilibrium systems with topological phases. After presenting some well-known examples of…

cond-mat1998

Perturbation Theory for Singular Potentials in Quantum Mechanics

Diptiman Sen

We study perturbation theory in certain quantum mechanics problems in which the perturbing potential diverges at some points, even though the energy eigenvalues are smooth function…

cond-mat.mes-hall2008

Line junction in a quantum Hall system with two filling fractions

Diptiman Sen, Amit Agarwal

We present a microscopic model for a line junction formed by counter or co-propagating single mode quantum Hall edges corresponding to different filling factors. The ends of the li…

cond-mat.str-el2001

Field theoretical study of a spin-1/2 ladder with unequal chain exchanges

Sujit Sarkar, Diptiman Sen

We study the low-energy properties of a Heisenberg spin-1/2 zigzag ladder with different exchange constants on the two chains. Using a nonlinear sigma-model field theory and abelia…

cond-mat.str-el2002

Study of Low-energy States of Clusters of Spin-1/2 and Spin-1 Triangles with Kagome-like Geometries

Indranil Rudra, S. Ramasesha, Diptiman Sen

We study the low-energy properties of Heisenberg antiferromagnetic spin-1/2 and spin-1 systems on various clusters made up of triangles. Some of the clusters have a geometry simila…

cond-mat.str-el2001

An introduction to bosonization and aome of its applications

Sumathi Rao, Diptiman Sen

We discuss the technique of bosonization for studying systems of interacting fermions in one dimension. After briefly reviewing the low-energy properties of Fermi and Luttinger liq…

cond-mat.mes-hall2011

Model of resistances in systems of Tomonaga-Luttinger liquid wires

Abhiram Soori, Diptiman Sen

In a recent paper, we combined the technique of bosonization with the concept of a Rayleigh dissipation function to develop a model for resistances in one-dimensional systems of in…

cond-mat.stat-mech2008

Quenching along a gapless line: A different exponent for defect density

Uma Divakaran, Amit Dutta, Diptiman Sen

We use a new quenching scheme to study the dynamics of a one-dimensional anisotropic spin-1/2 chain in the presence of a transverse field which alternates between the values $…

cond-mat1996

A comparative study of the phase diagrams of spin- and spin- antiferromagnetic chains with dimerization and frustration

Swapan Pati, R. Chitra, Diptiman Sen +2

We use the density matrix renormalization group method to study the ground state `phase' diagram and some low-energy properties of isotropic antiferromagnetic spin- and…

cond-mat.str-el2013

Quantum phases of dimerized and frustrated Heisenberg spin chains with s = 1/2, 1 and 3/2: an entanglement entropy and fidelity study

V. M. L. Durga Prasad Goli, Shaon Sahoo, S. Ramasesha +1

We study here different regions in phase diagrams of the spin-1/2, spin-1 and spin-3/2 one dimensional antiferromagnetic Heisenberg systems with frustration (next-nearest-neighbor…

cond-mat.mes-hall2003

Properties of low-lying states in some high-nuclearity Mn, Fe and V clusters: Exact studies of Heisenberg models

C. Raghu, Indranil Rudra, Diptiman Sen +1

Using an efficient numerical scheme that exploits spatial symmetries and spin parity, we have obtained the exact low-lying eigenstates of exchange Hamiltonians for the high nuclear…

cond-mat.str-el2023

Mechanisms of scrambling and unscrambling of quantum information in the ground state in spin chains: domain-walls, spin-flips and scattering phase shifts

Samudra Sur, Diptiman Sen

The spatiotemporal evolution of the out-of-time-order correlator (OTOC) measures the propagation and scrambling of local quantum information. For the transverse field Ising model w…

cond-mat.str-el2017

Density functional theory of the fractional quantum Hall effect

Jianyun Zhao, Manisha Thakurathi, Manish Jain +2

A conceptual difficulty in formulating the density functional theory of the fractional quantum Hall effect is that while in the standard approach the Kohn-Sham orbitals are either…

cond-mat.mes-hall2012

Junction between surfaces of two topological insulators

Diptiman Sen, Oindrila Deb

We study the properties of a line junction which separates the surfaces of two three-dimensional topological insulators. The velocities of the Dirac electrons on the two surfaces m…

physics.chem-ph2008

Fully Symmetrized VB Based Technique for Solving Exchange Hamiltonians of Molecular Magnets

Shaon Sahoo, Raghunathan Rajamani, S. Ramasesha +1

Generally, the first step in modeling molecular magnets involves obtaining the low-lying eigenstates of a Heisenberg exchange Hamiltonian which conserves total spin and belongs usu…

cond-mat.str-el2006

Gapless points of dimerized quantum spin chains: analytical and numerical studies

V. Ravi Chandra, Diptiman Sen, Naveen Surendran

We study the locations of the gapless points which occur for quantum spin chains of finite length (with a twisted boundary condition) at particular values of the nearest neighbor d…

cond-mat.str-el1997

A DMRG Study of Low-Energy Excitations and Low-Temperature Properties of Alternating Spin Systems

Swapan K. Pati, S. Ramasesha, Diptiman Sen

We use the density matrix renormalization group (DMRG) method to study the ground and low-lying excited states of three kinds of uniform and dimerized alternating spin chains. The…

hep-th2003

Novel multi-band quantum soliton states for a derivative nonlinear Schrodinger model

B. Basu-Mallick, Tanaya Bhattacharyya, Diptiman Sen

We show that localized N-body soliton states exist for a quantum integrable derivative nonlinear Schrodinger model for several non-overlapping ranges (called bands) of the coupling…

cond-mat.str-el2021

Thermodynamic behavior of modified integer-spin Kitaev models on the honeycomb lattice

Owen Bradley, Jaan Oitmaa, Diptiman Sen +1

We study the thermodynamic properties of modified spin- Kitaev models introduced by Baskaran, Sen and Shankar (Phys. Rev. B 78, 115116 (2008)). These models have the property th…

cond-mat.str-el2016

Signatures and conditions for phase band crossings in periodically driven integrable systems

Bhaskar Mukherjee, Arnab Sen, Diptiman Sen +1

We present generic conditions for phase band crossings for a class of periodically driven integrable systems represented by free fermionic models subjected to arbitrary periodic dr…

cond-mat.stat-mech2024

Weak universality, quantum many-body scars and anomalous infinite-temperature autocorrelations in a one-dimensional spin model with duality

Adithi Udupa, Samudra Sur, Sourav Nandy +2

We study a one-dimensional spin- model with three-spin interactions and a transverse magnetic field . The model has a symmetry, and a duality between a…

cond-mat.str-el2014

Studies on a frustrated Heisenberg spin chain with alternating ferromagnetic and antiferromagnetic exchanges

Shaon Sahoo, V. M. L. Durga Prasad Goli, Diptiman Sen +1

We study Heisenberg spin-1/2 and spin-1 chains with alternating ferromagnetic () and antiferromagnetic () nearest-neighbor interactions and a ferromagnetic next-neare…

cond-mat.stat-mech2024

Disconnected entanglement entropy as a marker of edge modes in a periodically driven Kitaev chain

Saikat Mondal, Diptiman Sen, Amit Dutta

We study the disconnected entanglement entropy (DEE) of a Kitaev chain in which the chemical potential is periodically modulated with -function pulses within the framework of F…

cond-mat.str-el2007

DMRG study of scaling exponents in spin-1/2 Heisenberg chains with dimerization and frustration

Manoranjan Kumar, S. Ramasesha, Diptiman Sen +1

In conformal field theory, key properties of spin-1/2 chains, such as the ground state energy per site and the excitation gap scale with dimerization delta as delta^alpha with know…

cond-mat.stat-mech1997

Quantization of the Derivative Nonlinear Schrodinger Equation

Diptiman Sen

We study the quantum mechanics of the derivative nonlinear Schrodinger equation which has appeared in many areas of physics and is known to be classically integrable. We find that…

cond-mat.str-el2003

Study of an Antiferromagnetic Sawtooth Chain with Spin-1/2 and Spin-1 sites

V. Ravi Chandra, Diptiman Sen, N. B. Ivanov +1

We study the low-energy properties of a sawtooth chain with spin-1's at the bases of the triangles and spin-1/2's at the vertices of the triangles. The spins have Heisenberg antife…

cond-mat1996

Novel correlations in two dimensions: Two-body problem

R. K. Bhaduri, Avinash Khare, J. Law +2

We discuss a many-body Hamiltonian with two- and three-body interactions in two dimensions introduced recently by Murthy, Bhaduri and Sen. Apart from an analysis of some exact solu…

cond-mat.dis-nn2023

Periodically driven model with quasiperiodic potential and staggered hopping amplitudes: engineering of mobility gaps and multifractal states

Sreemayee Aditya, K. Sengupta, Diptiman Sen

We study if periodic driving of a model with a quasiperiodic potential can generate interesting Floquet phases which have no counterparts in the static model. Specifically, we cons…