Universal Resistances of the Quantum RC circuit (2009)
Mora, Christophe, Hur, Karyn Le
We examine the concept of universal quantized resistance in the AC regime through the fully coherent quantum RC circuit comprising a cavity (dot) capacitively coupled to a gate and connected via a...
Quantum Phase Transitions in Spin-Boson Systems: Dissipation and Light Phenomena (2009)
Spin-boson models are essentially useful in the understanding of quantum optics, nuclear physics, quantum dissipation, and quantum computation. We discuss quantum phase transitions in various...
Theory of non-equilibrium transport in the SU(N) Kondo regime (2009)
Mora, Christophe, Vitushinsky, Pavel, Leyronas, Xavier, Clerk, Aashish A., Hur, Karyn Le
Using a Fermi liquid approach, we provide a comprehensive treatment of the current and current noise through a quantum dot whose low-energy behaviour corresponds to an SU($N$) Kondo model, focusing...
Superfluid-Mott Insulator Transition of Light in the Jaynes-Cummings Lattice (2009)
Regular arrays of electromagnetic resonators, in turn coupled coherently to individual quantum two-level systems, exhibit a quantum phase transition of polaritons from a superfluid phase to a...
Supersolidity of cold-atom Bose-Fermi mixtures in optical lattices (2009)
Orth, Peter P., Bergman, Doron L., Hur, Karyn Le
We investigate a cold atomic mixture of spinless bosons and fermions in two-dimensional optical lattices. In the presence of a nested Fermi surface, the bosons may develop a fascinating supersolid...
Hur, Karyn Le, Rice, T. Maurice
Since the discovery of high-temperature superconductivity in 1986 by Bednorz and Mueller, great efforts have been devoted to finding out how and why it works. From the d-wave symmetry of the order...
Non-equilibrium transport at a dissipative quantum phase transition (2008)
Chung, Chung-Hou, Hur, Karyn Le, Vojta, Matthias, Wölfle, Peter
We pioneerly investigate the non-equilibrium transport near a quantum phase transition in a generic and relatively simple case model, the dissipative resonant level model, that has many ramifications...
Near zero modes in condensate phases of the Dirac theory on the honeycomb lattice (2008)
Bergman, Doron L., Hur, Karyn Le
We investigate a number of fermionic condensate phases on the honeycomb lattice, to determine whether topological defects (vortices and edges) in these phases can support bound states with zero...
Charge Fractionalization in nonchiral Luttinger systems (2008)
Hur, Karyn Le, Halperin, Bertrand I., Yacoby, Amir
One-dimensional metals, such as quantum wires or carbon nanotubes, can carry charge in arbitrary units, smaller or larger than a single electron charge. However, according to Luttinger theory, which...
Discontinuous current-phase relations in small 1D Josephson junction arrays (2008)
We study the Josephson effect in small one-dimensional (1D) Josephson junction arrays. For weak Josephson tunneling, topologically different regions in the charge-stability diagram generate distinct...
The concept of entanglement entropy appears in multiple contexts, from black hole physics to quantum information theory, where it measures the entanglement of quantum states. We investigate the...
Dissipative Quantum Ising model in a cold atomic spin-boson mixture (2007)
Orth, Peter P., Stanic, Ivan, Hur, Karyn Le
Using cold bosonic atoms with two (hyperfine) ground states, we introduce a spin-boson mixture which allows to implement the quantum Ising model in a tunable dissipative environment. The first specie...
Double-gap superconducting proximity effect in nanotubes (2007)
Hur, Karyn Le, Vishveshwara, Smitha, Bena, Cristina
We theoretically explore the possibility of a superconducting proximity effect in single-walled metallic carbon nanotubes due to the presence of a superconducting substrate. An unconventional...
Entanglement and Criticality in Quantum Impurity Systems (2007)
Hur, Karyn Le, Doucet-Beaupre, Philippe, Hofstetter, Walter
We investigate the entanglement between a spin and its environment in impurity systems which exhibit a second-order quantum phase transition. As an application, we employ the spin-boson model,...
Universal and measurable entanglement entropy in the spin-boson model (2006)
We study the entanglement between a qubit and its environment from the spin-boson model with Ohmic dissipation. Through a mapping to the anisotropic Kondo model, we derive the entropy of entanglement...
Magnetically induced oscillations of the spin polarization in the Datta-Das geometry (2006)
Nevidomskyy, Andriy H., Hur, Karyn Le
The control of intrinsic magnetic degrees of freedom is very important as it offers a practical means to manipulate and probe electron spin transport. Tunable spin-orbit effect in quantum wires can...
The electron lifetime in Luttinger liquids (2006)
We investigate the decoherence of the electron wavepacket in purely ballistic one-dimensional systems described through the Luttinger liquid (LL). At a finite temperature $T$ and long times $t$, we...
Heavy electrons from Hund's rule and short-range Antiferromagnetism (2006)
We investigate the one-dimensional ferromagnetic Kondo lattice in the hole-rich region. Of interest to us is the intermediate situation where the ferromagnetic Kondo coupling (Hund's coupling) is...
Coulomb drag between two spin incoherent Luttinger liquids (2005)
Fiete, Gregory A., Hur, Karyn Le, Balents, Leon
In a one dimensional electron gas at low enough density, the magnetic (spin) exchange energy $J$ between neighboring electrons is exponentially suppressed relative to the characteristic charge...
A Mesoscopic Resonating Valence Bond system on a triple dot (2005)
Hur, Karyn Le, Recher, Patrik, Dupont, Emilie, Loss, Daniel
We introduce a mesoscopic pendulum from a triple dot. The pendulum is fastened through a singly-occupied dot (spin qubit). Two other strongly capacitively islands form a double-dot charge qubit with...
Decoherence of Einstein-Podolsky-Rosen pairs in a noisy Andreev entangler (2005)
We investigate quantum noise effect on the transportation of nonlocal Cooper pairs accross the realistic Andreev entangler which consists of an s-wave superconductor coupled to two small quantum dots...
Transport in a spin incoherent Luttinger liquid (2005)
Fiete, Gregory A., Hur, Karyn Le, Balents, Leon
We theoretically investigate transport in a spin incoherent one dimensional electron system, which may be realized in quantum wires at low electron density and finite temperature. Both the pure and...
Dephasing from electron fractionalization (2005)
We investigate the dephasing of mesoscopic interferences by electron-electron interactions in a strictly one-dimensional geometry composed of two weakly-coupled (clean and very long) Luttinger...
Hidden Caldeira-Leggett dissipation in a Bose-Fermi Kondo model (2005)
Li, Mei-Rong, Hur, Karyn Le, Hofstetter, Walter
We show that the Bose-Fermi Kondo model (BFKM), which may find applicability both to certain dissipative mesoscopic qubit devices and to heavy fermion systems described by the Kondo lattice model,...
Unification of electromagnetic noise and Luttinger liquid via a quantum dot (2004)
We investigate the effect of dissipation on a small quantum dot (resonant level) tunnel-coupled to a chiral Luttinger liquid (LL) with the LL parameter $K$. The dissipation stems from the coupling of...
Do quantum dots allow one access to pseudogap Kondo physics? (2004)
Hopkinson, John, Hur, Karyn Le, Dupont, Emilie
For the last decade, tunable quantum dot systems have allowed the investigation of Kondo physics wherein the quenching of a single spin on an artificial atom affects the conductance. The pseudogap...
Double-dot charge qubit and transport via dissipative cotunneling (2004)
We investigate transport through an exotic ``charge'' qubit composed of two strongly capacitively coupled quantum dots (QDs), each being independently connected to a side gate which in general...
Probing spin and orbital Kondo effects with a mesoscopic interferometer (2004)
Lopez, Rosa, Sanchez, David, Lee, Minchul, Choi, Mahn-Soo, Simon, Pascal, Hur, Karyn Le
We investigate theoretically the transport properties of a closed Aharonov-Bohm interferometer containing two quantum dots in the strong coupling regime. We find two distinct physical scenarios...
Coulomb blockade of a noisy metallic box: A realization of Bose-Fermi Kondo models (2003)
We focus on a metallic quantum dot coupled to a reservoir of electrons through a single-mode quantum point contact and capacitively connected to a back-gate, by taking into account that the gate...
Maximized Orbital and Spin Kondo effects in a single-electron transistor (2003)
Hur, Karyn Le, Simon, Pascal, Borda, Laszlo
We investigate the charge fluctuations of a single-electron box (metallic grain) coupled to a lead via a smaller quantum dot in the Kondo regime. The most interesting aspect of this problem resides...
Smearing of charge fluctuations in a grain by spin-flip assisted tunneling (2002)
We investigate the charge fluctuations of a grain (large dot) coupled to a lead via a small quantum dot in the Kondo regime. We show that the strong entanglement of charge and spin flips in this...
Fractional plateaus in the Coulomb blockade of coupled quantum dots (2002)
Ground-state properties of a double-large-dot sample connected to a reservoir via a single-mode point contact are investigated. When the interdot transmission is perfect and the dots controlled by...
Capacitance of a quantum dot from the channel-anisotropic two-channel Kondo model (2001)
We investigate the charge fluctuations of a large quantum dot coupled to a two-dimensional electron gas via a quantum point contact following the work of Matveev. We limit our discussion to the case...
Electron fractionalization induced dephasing in Luttinger liquids (2001)
Using the appropriate fractionalization mechanism, we correctly derive the temperature (T) and interaction dependence of the electron lifetime $\tau_F$ in Luttinger liquids. For strong enough...
Andreev scattering in the asymmetric ladder with preformed bosonic pairs (2001)
We discuss the phase coherence which emanates from the ladder-like proximity effect between a ``weak superconductor'' with preformed bosonic pairs (here, a single-chain Luther-Emery liquid with...
Zeeman smearing of the Coulomb blockade (2001)
Charge fluctuations of a large quantum dot coupled to a two-dimensional lead via a single-mode good Quantum Point Contact (QPC) and capacitively coupled to a back-gate, are investigated in the...
Weakly-coupled Hubbard chains at half-filling and Confinement (2000)
We study two (very) weakly-coupled Hubbard chains in the half-filled case, and especially the situation where the intrachain Mott scale $m$ is much larger than the bare single-electron interchain...
Successive opening of the Fermi surface in doped N-leg Hubbard ladders (2000)
Ledermann, Urs, Hur, Karyn Le, Rice, T. M.
We study the effect of doping away from half-filling in weakly (but finitely) interacting N-leg Hubbard ladders using renormalization group and bosonization techniques. For a small on-site repulsion...
Metal-Kondo insulating transitions and transport in one dimension (2000)
We study two different metal-insulating transitions possibly occurring in one-dimensional Kondo lattices. First, we show how doping the pure Kondo lattice model in the strong-coupling limit, results...
Kondo effect in a one dimensional d-wave superconductor (1999)
We derive a solvable resonant-level type model, to describe an impurity spin coupled to zero-energy bound states localized at the edge of a one dimensional d-wave superconductor. This results in a...
Kondo effect in crossed Luttinger liquids (1999)
We study the Kondo effect in two crossed Luttinger liquids, using Boundary Conformal Field Theory. We predict two types of critical behaviors: either a two-channel Kondo fixed point with a...
Phases of the two-band model of spinless fermions in one dimension (1999)
We study the two-band model of spinless fermions in one dimension for weak repulsive interactions. In this case, the model is equivalent to the weakly interacting spinless two-leg ladder. We obtain...
The underscreened Kondo effect in ladder systems (1999)
We introduce a new Kondo ladder model by coupling the well-known Takhtajan-Babujan S=1 chain to a half-filled one-dimensional electron gas, and we solve it using quantum field theory techniques....
Critical Ising modes in low-dimensional Kondo insulators (1999)
We present an Ising-like intermediate phase for one-dimensional Kondo insulator systems. Resulting from a spinon splitting, its low-energy excitations are critical Ising modes, whereas the triplet...
Kondo effect in a Luttinger liquid: nonuniversality of the Wilson ratio (1999)
Using a precise coset Ising-Bose representation, we show how backscattering of electrons off a magnetic impurity destabilizes the two-channel Kondo fixed point and drives the system to a new fixed...
The underscreened Kondo effect: a two S=1 impurity model (1997)
The underscreened Kondo effect is studied within a model of two impurities S=1 interacting with the conduction band and via an interimpurity coupling $K\vec{S_1}.\vec{S_2}$. Using a mean-field...
We investigate the one-dimensional Kondo lattice model (1D KLM) for ferromagnetic Kondo couplings, by using the bosonization method. The ferromagnet ic 2-leg spin ladder and the S=1 antiferromagnet...