Sagnac interference in carbon nanotubes (2008)
Bishara, Waheb, Refael, Gil, Bockrath, Marc
The Sagnac interference mode arises when two interfering counterpropogating beams traverse a loop, but with their velocities detuned by a small amount 2u, with vR/L=vF±u. In this paper we perform a...
Dissipation-Driven Quantum Phase Transition in Superconductor-Graphene Systems (2008)
Lutchyn, Roman M., Galitski, Victor M., Refael, Gil, Das Sarma, S.
We show that a system of Josephson junctions coupled via low-resistance tunneling contacts to graphene substrate(s) may effectively operate as a current switching device. The effect is based on the...
Dissipation-Driven Quantum Phase Transition in Superconductor-Graphene Systems (2008)
Lutchyn, Roman M., Galitski, Victor M., Refael, Gil, Das Sarma, S.
We show that a system of Josephson junctions coupled via low-resistance tunneling contacts to graphene substrate(s) may effectively operate as a current switching device. The effect is based on the...
Infinite Randomness Phases and Entanglement Entropy of the Disordered Golden Chain (2008)
Fidkowski, Lukasz, Refael, Gil, Bonesteel, Nick, Moore, Joel
Topological insulators supporting non-abelian anyonic excitations are at the center of attention as candidates for topological quantum computation. In this paper, we analyze the ground-state...
Dissipation-driven quantum phase transition in superconductor-graphene systems (2008)
Lutchyn, Roman M., Galitski, Victor, Refael, Gil, Sarma, S. Das
We show that a system of Josephson junctions coupled via low-resistance tunneling contacts to graphene substrate(s) may effectively operate as a current switching device. The effect is based on the...
Sagnac interference in Carbon nanotubes (2008)
Bishara, Waheb, Refael, Gil, Bockrath, Marc
The Sagnac interference mode arises when two interfering counterpropogating beams traverse a loop, but with their velocities detuned by a small amount $2u$, with $v_{R/L}=v_F\pm u$. In this paper we...
Insulating Phases and Superfluid-Insulator Transition of Disordered Boson Chains (2008)
Altman, Ehud, Kafri, Yariv, Polkovnikov, Anatoli, Refael, Gil
Using a strong disorder real-space renormalization group, we study the phase diagram of a fully disordered chain of interacting bosons. Since this approach does not suffer from runaway flows, it...
Vortex lattice locking in rotating two-component Bose–Einstein condensates (2008)
Barnett, Ryan, Refael, Gil, Porter, Mason A., Büchler, Hans Peter
The vortex density of a rotating superfluid, divided by its particle mass, dictates the superfluid's angular velocity through the Feynman relation. To find how the Feynman relation applies to...
Effect of inhomogeneous coupling on BCS superconductors (2008)
Zou, Yue, Klich, Israel, Refael, Gil
We investigate the influence of inhomogeneity in the pairing coupling constant U(r-vector) on dirty BCS superconductors, focusing on Tc, the order parameter Delta(r-vector), and the energy gap...
Superconductor-to-normal transition in finite nanowires (2008)
Refael, Gil, Demler, Eugene, Oreg, Yuval
In this paper we discuss the interplay of quantum fluctuations and dissipation in uniform superconducting nanowires. We consider a phenomenological model with superconducting and normal components,...
Superfluid-insulator transition in Fermi-Bose mixtures and the orthogonality catastrophe (2007)
The superfluid-insulator transition of bosons is strongly modified by the presence of Fermions. Through an imaginary-time path integral approach, we derive the self-consistent mean-field transition...
Effect of inhomogeneous coupling on superconductivity (2007)
Zou, Yue, Klich, Israel, Refael, Gil
We investigate the influence of inhomogeneity in the pairing coupling constant $U(\vec r)$ on dirty BCS superconductors, focusing on $T_c$, the order parameter $\Delta(\vec r)$, and the energy gap...
The insulating phases and superfluid-insulator transition of disordered boson chains (2007)
Altman, Ehud, Kafri, Yariv, Polkovnikov, Anatoli, Refael, Gil
Using a strong disorder real-space renormalization group (RG), we study the phase diagram of a fully disordered chain of interacting bosons. Since this approach does not suffer from run-away flows,...
Sharp Superconductor-Insulator Transition in Short Wires (2007)
Meidan, Dganit, Oreg, Yuval, Refael, Gil, Smith, Robert A.
Recent experiments on short MoGe nanowires show a sharp superconductor-insulator transition tuned by the normal state resistance of the wire, with a critical resistance of $R_c\approx R_Q= h/(4e^2)$....
Universal Periods in Quantum Hall Droplets (2007)
Fiete, Gregory A., Refael, Gil, Fisher, Matthew P. A.
Using the hierarchy picture of the fractional quantum Hall effect, we study the ground-state periodicity of a finite size quantum Hall droplet in a quantum Hall fluid of a different filling factor....
Sagnac Interference in Carbon Nanotube Loops (2007)
Refael, Gil, Heo, Jinseong, Bockrath, Marc
In this Letter we study electron interference in nanotube loops. The conductance as a function of the applied voltage is shown to oscillate due to interference between electron beams traversing the...
Vortex Lattice Locking in Rotating Two-Component Bose-Einstein Condensates (2007)
Barnett, Ryan, Refael, Gil, Porter, Mason A., Buchler, Hans Peter
The vortex density of a rotating superfluid, divided by its particle mass, dictates the superfluid's angular velocity through the Feynman relation. To find how the Feynman relation applies to...
Universal Periods in Quantum Hall Droplets (2007)
Fiete, Gregory A., Refael, Gil, Fisher, Matthew P. A.
Using the hierarchy picture of the fractional quantum Hall effect, we study the the ground state periodicity of a finite size quantum Hall droplet in a quantum Hall fluid of a different filling...
Sharp Superconductor-Insulator Transition in Short Wires (2007)
Meidan, Dganit, Oreg, Yuval, Refael, Gil
Recent experiments on short MoGe nanowires show a sharp superconducting-insulating transition at the universal resistance RQ=h/(4e^2), contrary to the expectation of a smooth temperature dependence...
Superfluidity and magnetism in multicomponent ultracold fermions (2007)
Cherng, R. W., Refael, Gil, Demler, Eugene
We study the interplay between superfluidity and magnetism in a multicomponent gas of ultracold fermions. Ward-Takahashi identities constrain possible mean-field states describing order parameters...
Entanglement entropy of the random spin-1 Heisenberg chain (2007)
Random spin chains at quantum critical points exhibit an entanglement entropy between a segment of length L and the rest of the chain that scales as log_2 L with a universal coefficient. Since for...
Superconductor-to-normal transitions in dissipative chains of mesoscopic grains and nanowires (2007)
Refael, Gil, Demler, Eugene, Oreg, Yuval, Fisher, Daniel S.
The interplay of quantum fluctuations and dissipation in chains of mesoscopic superconducting grains is analyzed and the results are applied to nanowires. It is shown that in one dimensional arrays...
The Effect of Quantum Phase Slip Interactions on the Transport of Thin Superconducting Wires (2006)
Meidan, Dganit, Oreg, Yuval, Refael, Gil
We study theoretically the effect of interactions between quantum phase slips in a short superconducting wire beyond the dilute phase slip approximation. In contrast to the smooth transition in...
Transverse Meissner physics of planar superconductors with columnar pins (2006)
Refael, Gil, Hofstetter, Walter, Nelson, David R.
The statistical mechanics of thermally excited vortex lines with columnar defects can be mapped onto the physics of interacting quantum particles with quenched random disorder in one less dimension....
Measuring entanglement entropies in many-body systems (2006)
Klich, Israel, Refael, Gil, Silva, Alessandro
We explore the relation between entanglement entropy of quantum many-body systems and the distribution of corresponding, properly selected, observables. Such a relation is necessary to actually...
Sagnac interference in Carbon nanotube loops (2006)
Refael, Gil, Heo, Jinseong, Bockrath, Marc
In this paper we study electron interference in nanotube loops. The conductance as a function of the applied voltage is shown to oscillate due to interference between electron beams traversing the...
Transverse Meissner Physics of Planar Superconductors with Columnar Pins (2006)
Refael, Gil, Hofstetter, Walter, Nelson, David R.
The statistical mechanics of thermally excited vortex lines with columnar defects can be mapped onto the physics of interacting quantum particles with quenched random disorder in one less dimension....
Universal point contact resistance between thin-film superconductors (2006)
Hermele, Michael, Refael, Gil, Fisher, Matthew P. A., Goldbart, Paul M.
A system comprising two superconducting thin films connected by a point contact is considered. The contact resistance is calculated as a function of temperature and film geometry, and is found to...
Towards measuring Entanglement Entropies in Many Body Systems (2006)
Klich, Israel, Refael, Gil, Silva, Alessandro
We explore the relation between entanglement entropy of quantum many body systems and the distribution of corresponding, properly selected, observables. Such a relation is necessary to actually...
Simulation results for an interacting pair of resistively shunted Josephson junctions (2005)
Werner, Philipp, Refael, Gil, Troyer, Matthias
Using a new cluster Monte Carlo algorithm, we study the phase diagram and critical properties of an interacting pair of resistively shunted Josephson junctions. This system models tunnelling between...
Universal point contact resistance between thin-film superconductors (2005)
Hermele, Michael, Refael, Gil, Fisher, Matthew P. A., Goldbart, Paul M.
A system comprising two superconducting thin films connected by a point contact is considered. The contact resistance is calculated as a function of temperature and film geometry, and is found to...
Superconductor-to-Metal Transitions in Dissipative Chains of Mesoscopic Grains and Nanowires (2005)
Refael, Gil, Demler, Eugene, Oreg, Yuval, Fisher, Daniel S.
The interplay of quantum fluctuations and dissipation in chains of mesoscopic superconducting grains is analyzed, and the results are also applied to nanowires. It is shown that in 1-d arrays of...
Ground-state degeneracy of correlated insulators with edges (2005)
Using the topological flux insertion procedure, the ground-state degeneracy of an insulator on a periodic lattice with filling factor nu=p/q was found to be at least q-fold. Applying the same...
Fate of the Josephson effect in thin-film superconductors (2005)
Hermele, Michael, Refael, Gil, Fisher, Matthew P. A., Goldbart, Paul M.
The dc Josephson effect refers to the dissipationless electrical current -- the supercurrent -- that can be sustained across a weak link connecting two bulk superconductors. This effect is a probe of...
Simulation results for an interacting pair of resistively shunted Josephson junctions (2005)
Werner, Philipp, Refael, Gil, Troyer, Matthias
Using a new cluster Monte Carlo algorithm, we study the phase diagram and critical properties of an interacting pair of resistively shunted Josephson junctions. This system models tunneling between...
Phase Transition in a System of One-Dimensional Bosons with Strong Disorder (2004)
Altman, Elud, Kafri, Yariv, Polkovnikov, Anatoli, Refael, Gil
We study one-dimensional disordered bosons at large commensurate filling. Using a real space renormalization group approach, we find a new random fixed point which controls a phase transition from a...
Ground-State Degeneracy of Correlated Insulators with Edges (2004)
Using the topological flux insertion procedure, the ground-state degeneracy of an insulator on a periodic lattice with filling factor $\nu=p/q$ was found to be at least $q$-fold. Applying the same...
Energy correlations in random transverse field Ising spin chains (2004)
Refael, Gil, Fisher, Daniel S.
The end-to-end energy-energy correlations of random transverse field quantum Ising spin chains are computed using a generalization of an asymptotically exact real space renormalization group (RG)...
Phase transition of one dimensional bosons with strong disorder (2004)
Altman, Ehud, Kafri, Yariv, Polkovnikov, Anatoli, Refael, Gil
We study one dimensional disordered bosons at large commensurate filling. Using a real space renormalization group approach we find a new random fixed point which controls a phase transition from a...
Dissipation and quantum phase transitions of a pair of Josephson junctions (2003)
Refael, Gil, Demler, Eugene, Oreg, Yuval, Fisher, Daniel S.
A model system consisting of a mesoscopic superconducting grain coupled by Josephson junctions to two macroscopic superconducting electrodes is studied. We focus on the effects of Ohmic dissipation...
Energy Correlations In Random Transverse Field Ising Spin Chains (2003)
Refael, Gil, Fisher, Daniel S.
The end-to-end energy - energy correlations of random transverse-field quantum Ising spin chains are computed using a generalization of an asymptotically exact real-space renormalization group...
Dissipation and quantum phase transitions of a pair of Josephson junctions (2003)
Refael, Gil, Demler, Eugene, Oreg, Yuval, Fisher, Daniel S.
A model system consisting of a mesoscopic superconducting grain coupled by Josephson junctions to two macroscopic superconducting electrodes is studied. We focus on the effects of ohmic dissipation...
Thesis (Ph. D., Dept. of Physics)--Harvard University, 2003.
Spin reduction transition in spin-3/2 random Heisenberg chains (2002)
Refael, Gil, Kehrein, Stefan, Fisher, Daniel S.
Random spin-3/2 antiferromagnetic Heisenberg chains are investigated using an asymptotically exact renormalization group. Randomness is found to induce a quantum phase transition between two...
Spin Reduction Transition in Spin-3/2 Random Heisenberg Chains (2001)
Refael, Gil, Kehrein, Stefan, Fisher, Daniel S.
Random spin-3/2 antiferromagnetic Heisenberg chains are investigated using an asymptotically exact renormalization group. Randomness is found to induce a quantum phase transition between two...