Quantum Hall to Insulator Transition in the Bilayer Quantum Hall Ferromagnet (2008)
Murthy, Ganpathy, Sachdev, Subir
We describe a new phase transition of the bilayer quantum Hall ferromagnet at filling fraction $\nu = 1$. In the presence of static disorder (modeled by a periodic potential), bosonic $S=1/2$ spinons...
Diamagnetic persistent currents for electrons in ballistic billiards subject to a point flux (2008)
Zelyak, Oleksandr, Murthy, Ganpathy
We study the persistent current of noninteracting electrons subject to a pointlike magnetic flux in the simply connected chaotic Robnik-Berry quantum billiard, and also in an annular analog thereof....
A Universal Interacting Crossover Regime in Two-Dimensional Quantum Dots (2007)
Interacting electrons in quantum dots with large Thouless number $g$ in the three classical random matrix symmetry classes are well-understood. When a specific type of spin-orbit coupling known to be...
The Hamiltonian Theory of the fractional quantum Hall effect is an operator description that subsumes many properties of Composite Fermions, applies to gapped and gapless cases, and has been found to...
Zelyak, Oleksandr, Murthy, Ganpathy, Rozhkov, Igor
We study a system of two quantum dots connected by a hopping bridge. Both the dots and connecting region are assumed to be in universal crossover regimes between Gaussian Orthogonal and Unitary...
Large spin-orbit effects in small quantum dots (2006)
We consider small ballistic quantum dots weakly coupled to the leads in the chaotic regime and look for significant spin-orbit effects. We find that these effects can become quite prominent in the...
Deconfinement in d=1: A closer look (2005)
The notion of deconfinement in two d=1 models, the Schwinger model and the Heisenberg chain, is re-examined. Both have half-asymptotic excitations (where particles and antiparticles must alternate)...
Rozhkov, Igor, Murthy, Ganpathy
We focus on the problem of an impurity-free billiard with a random position-dependent boundary coupling to the environment. The response functions of such an open system can be obtained...
Coherence Network in the Quantum Hall Bilayer (2005)
Fertig, H. A., Murthy, Ganpathy
Recent experiments on quantum Hall bilayers near total filling factor 1 have demonstrated that they support an ``imperfect'' two-dimensional superfluidity, in which there is nearly dissipationless...
A nearly closed ballistic billiard with random boundary transmission (2005)
Rozhkov, Igor, Murthy, Ganpathy
A variety of mesoscopic systems can be represented as a billiard with a random coupling to the exterior at the boundary. Examples include quantum dots with multiple leads, quantum corrals with...
Murthy, Ganpathy, Shankar, R., Mathur, Harsh
In previous work we have found a regime in ballistic quantum dots where interelectron interactions can be treated asymptotically exactly as the Thouless number $g$ of the dot becomes very large....
Interplay between the mesoscopic Stoner and Kondo effects in quantum dots (2004)
We consider electrons confined to a quantum dot interacting antiferromagnetically with a spin-$\half$ Kondo impurity. The electrons also interact among themselves ferromagnetically with a...
Quantum dots with large Thouless number $g$ embody a regime where both disorder and interactions can be treated nonperturbatively using large-N techniques (with $N=g$) and quantum phase transitions...
Collective edge modes in fractional quantum Hall systems (2004)
Nguyen, Hoang K., Joglekar, Yogesh N., Murthy, Ganpathy
Over the past few years one of us (Murthy) in collaboration with R. Shankar has developed an extended Hamiltonian formalism capable of describing the ground state and low energy excitations in the...
Absence of U(1) spin liquids in two dimensions (2003)
Herbut, Igor F., Seradjeh, Babak H., Sachdev, Subir, Murthy, Ganpathy
Many popular models of fractionalized spin liquids contain neutral fermionic spinon excitations on a Fermi surface, carrying unit charges under a compact U(1) gauge force. We argue that instanton...
Murthy, Ganpathy, Shankar, R., Herman, Damir, Mathur, Harsh
We provide a framework for analyzing the problem of interacting electrons in a ballistic quantum dot with chaotic boundary conditions within an energy $E_T$ (the Thouless energy) of the Fermi energy....
Herman, Damir, Mathur, Harsh, Murthy, Ganpathy
Recently, new strongly interacting phases have been uncovered in mesoscopic systems with chaotic scattering at the boundaries by two of the present authors and R. Shankar. This analysis is reliable...
Edge reconstructions in fractional quantum Hall systems (2003)
Joglekar, Yogesh N., Nguyen, Hoang K., Murthy, Ganpathy
Two dimensional electron systems exhibiting the fractional quantum Hall effects are characterized by a quantized Hall conductance and a dissipationless bulk. The transport in these systems occurs...
Quantum Dots with Disorder and Interactions: A Solvable Large-g Limit (2002)
We show that problem of interacting electrons in a quantum dot with chaotic boundary conditions is solvable in the large-g limit, where g is the dimensionless conductance of the dot. The critical...
Hamiltonian Theories of the FQHE (2002)
This paper reviews progress on the Fractional Quantum Hall Effect (FQHE) based on what we term hamiltonian theories, i.e., theories that proceed from the microscopic electronic hamiltonian to the...
Interactions and Disorder in Quantum Dots: Instabilities and Phase Transitions (2002)
Murthy, Ganpathy, Mathur, Harsh
Using a fermionic renormalization group approach we analyse a model where the electrons diffusing on a quantum dot interact via Fermi-liquid interactions. Describing the single-particle states by...
Hamiltonian Theory of the Fractional Quantum Hall Effect: Effect of Landau Level Mixing (2002)
We derive an effective hamiltonian in the Lowest Landau Level (LLL) that incorporates the effects of Landau-level mixing to all higher Landau levels to leading order in the ratio of interaction...
The Effects of Disorder on the $\nu=1$ Quantum Hall State (2001)
A disorder-averaged Hartree-Fock treatment is used to compute the density of single particle states for quantum Hall systems at filling factor $\nu=1$. It is found that transport and spin...
Hamiltonian Theory of the FQHE: Conserving Approximation for Incompressible Fractions (2001)
A microscopic Hamiltonian theory of the FQHE developed by Shankar and the present author based on the fermionic Chern-Simons approach has recently been quite successful in calculating gaps and finite...
Hamiltonian Theory of the Composite Fermion Wigner Crystal (2001)
Narevich, R., Murthy, Ganpathy, Fertig, H. A.
Experimental results indicating the existence of the high magnetic field Wigner Crystal have been available for a number of years. While variational wavefunctions have demonstrated the instability of...
Using the Hamiltonian formulation of Composite Fermions developed recently, the temperature dependence of the spin polarization is computed for the translationally invariant fractional quantum Hall...
Temperature dependence of the spin polarization in the fractional quantum Hall effects (2000)
Using a Hamiltonian formulation of Composite Fermions that I recently developed with R. Shankar, I compute the dependence of the spin polarization on the temperature for the translationally invariant...
Hall Crystal States at $\nu=2$ and Moderate Landau Level Mixing (2000)
The $\nu=2$ quantum Hall state at low Zeeman coupling is well-known to be a translationally invariant singlet if Landau level mixing is small. At zero Zeeman interaction, as Landau level mixing...
It is well-known that the 2/5 state is unpolarized at zero Zeeman energy, while it is fully polarized at large Zeeman energies. A novel state with charge/spin density wave order for Composite...
Hamiltonian Description of Composite Fermions: Magnetoexciton Dispersions (1999)
A microscopic Hamiltonian theory of the FQHE, developed by Shankar and myself based on the fermionic Chern-Simons approach, has recently been quite successful in calculating gaps in Fractional...
Scaling Relations for Gaps in Fractional Quantum Hall States (1998)
Murthy, Ganpathy, Park, K., Shankar, R., Jain, J. K.
The microscopic approach of Murthy and Shankar, which has recently been used to calculate the transport gaps of quantum Hall states with fractions p/(2ps+1), also implies scaling relations between...
Hamiltonian Description of Composite Fermions: Calculation of Gaps (1998)
We analytically calculate gaps for the 1/3, 2/5, and 3/7 polarized and partially polarized Fractional Quantum Hall states based on the Hamiltonian Chern-Simons theory we have developed. For a class...
Field Theory of the Fractional Quantum Hall Effect-I (1998)
We provide details of a shorter letter and cond-mat/9702098 and some new results. We describe a Chern-Simons theory for the fractional quantum Hall states in which magnetoplasmon degrees of freedom...
Towards a field theory of the fractional quantum Hall states (1997)
We present a Chern-Simons theory of the fractional quantum Hall effect in which flux attachment is followed by a transformation that effectively attaches the correlation holes. We extract the...
Superfluids and Supersolids on Frustrated 2D Lattices (1996)
Murthy, Ganpathy, Arovas, Daniel, Auerbach, Assa
We study the ground state of hard-core bosons with nearest-neighbor hopping and nearest-neighbor interactions on the triangular and Kagom\'e lattices by mapping to a system of spins ($S={1\over2}$),...
Novel Phases of Planar Fermionic Systems (1995)
We discuss a {\em family} of planar (two-dimensional) systems with the following phase strucure: a Fermi liquid, which goes by a second order transition (with non classical exponent even in...
Renormalization Group Approach to the Coulomb Pseudopotential for C_{60} (1994)
Berdenis, Nikos, Murthy, Ganpathy
A numerical renormalization group technique recently developed by one of us is used to analyse the Coulomb pseudopotential (${\mu^*}$) in ${{\rm C}_{60}}$ for a variety of bare potentials. We find a...