Near action-degenerate periodic-orbit bunches: A skeleton of chaos (2009)
Altland, Alexander, Braun, Petr, Haake, Fritz, Heusler, Stefan, Knieper, Gerhard, Müller, Sebastian
Long periodic orbits of hyperbolic dynamics do not exist as independent individuals but rather come in closely packed bunches. Under weak resolution a bunch looks like a single orbit in configuration...
Periodic-orbit theory of universal level correlations in quantum chaos (2009)
Müller, Sebastian, Heusler, Stefan, Altland, Alexander, Braun, Petr, Haake, Fritz
Using Gutzwiller's semiclassical periodic-orbit theory we demonstrate universal behaviour of the two-point correlator of the density of levels for quantum systems whose classical limit is fully...
Quantum generalization of the quasiclassical approach to chaotic dynamics (2009)
Micklitz, T., Altland, Alexander
We discuss a quantum generalization of the quasiclassical Eilenberger equation for chaotic systems. Within the generalized framework, a conspiracy of quantum uncertainty and hyperbolic dynamics leads...
Nonequilibrium dephasing in Coulomb blockade quantum dots (2008)
Altland, Alexander, Egger, Reinhold
We present a theory of zero-bias anomalies and dephasing rates for a Coulomb-blockaded quantum dot, driven out of equilibrium by coupling to voltage biased source and drain leads. We interpret our...
Low-energy theory of disordered interacting quantum wires (2008)
Micklitz, T., Altland, Alexander, Meyer, Julia S.
We derive an effective low-energy theory of disordered interacting quantum wires. Our theory describes Anderson localization in the limit of vanishing dephasing and reduces to standard abelian...
Anderson localization from classical trajectories (2008)
Brouwer, Piet W., Altland, Alexander
We show that Anderson localization in quasi-one dimensional conductors with ballistic electron dynamics, such as an array of ballistic chaotic cavities connected via ballistic contacts, can be...
Many body generalization of the Landau Zener problem (2007)
Altland, Alexander, Gurarie, V.
We formulate and approximately solve a specific many-body generalization of the Landau-Zener problem. Unlike with the single particle Landau-Zener problem, our system does not abide in the adiabatic...
Universal spectral correlations from the ballistic sigma model (2007)
Müller, Jan, Micklitz, Tobias, Altland, Alexander
We consider the semiclassical ballistic sigma-model as an effective theory describing the quantum mechanics of classically chaotic systems. Specifically, we elaborate on close analogies to the...
Periodic-Orbit Theory of Level Correlations (2006)
Heusler, Stefan, Müller, Sebastian, Altland, Alexander, Braun, Petr, Haake, Fritz
We present a semiclassical explanation of the so-called Bohigas-Giannoni-Schmit conjecture which asserts universality of spectral fluctuations in chaotic dynamics. We work with a generating function...
Low energy theory of disordered graphene (2006)
At low values of external doping graphene displays a wealth of unconventional transport properties. Perhaps most strikingly, it supports a robust 'metallic' regime, with universal conductance of the...
Interplay of Ehrenfest time and dephasing time in ballistic conductors (2006)
Altland, Alexander, Brouwer, Piet W., Tian, Chushun
Quantum interference corrections in ballistic conductors require a minimal time: the Ehrenfest time. In this letter, we investigate the fate of the interference corrections to quantum transport in...
From Luttinger liquid to Altshuler-Aronov anomaly in multi-channel quantum wires (2006)
Mora, Christophe, Egger, Reinhold, Altland, Alexander
A crossover theory connecting Altshuler-Aronov electron-electron interaction corrections and Luttinger liquid behavior in quasi-1D disordered conductors has been formulated. Based on an interacting...
Spectral correlations of individual quantum graphs (2005)
Gnutzmann, Sven, Altland, Alexander
We investigate the spectral properties of chaotic quantum graphs. We demonstrate that the `energy'--average over the spectrum of individual graphs can be traded for the functional average over a...
Inelastic electron transport in granular arrays (2005)
Altland, Alexander, Glazman, Leonid I., Kamenev, Alex, Meyer, Julia S.
Transport properties of granular systems are governed by Coulomb blockade effects caused by the discreteness of the electron charge. We show that, in the limit of vanishing mean level spacing on the...
Anderson localization from the replica formalism (2005)
Altland, Alexander, Kamenev, Alex, Tian, Chushun
We study Anderson localization in quasi--one--dimensional disordered wires within the framework of the replica $\sigma$--model. Applying a semiclassical approach (geodesic action plus Gaussian...
Periodic-Orbit Theory of Universality in Quantum Chaos (2005)
Müller, Sebastian, Heusler, Stefan, Braun, Petr, Haake, Fritz, Altland, Alexander
We argue semiclassically, on the basis of Gutzwiller's periodic-orbit theory, that full classical chaos is paralleled by quantum energy spectra with universal spectral statistics, in agreement with...
Field Theory Approach to Quantum Interference in Chaotic Systems (2004)
Müller, Jan, Altland, Alexander
We consider the spectral correlations of clean globally hyperbolic (chaotic) quantum systems. Field theoretical methods are applied to compute quantum corrections to the leading (`diagonal')...
Universal spectral statistics in quantum graphs (2004)
Gnutzmann, Sven, Altland, Alexander
We prove that the spectrum of an individual chaotic quantum graph shows universal spectral correlations, as predicted by random--matrix theory. The stability of these correlations with regard to...
Semiclassical Foundation of Universality in Quantum Chaos (2004)
Müller, Sebastian, Heusler, Stefan, Braun, Petr, Haake, Fritz, Altland, Alexander
We sketch the semiclassical core of a proof of the so-called Bohigas-Giannoni-Schmit conjecture: A dynamical system with full classical chaos has a quantum energy spectrum with universal fluctuations...
Electron Transport in Granular Metals (2003)
Altland, Alexander, Glazman, Leonid I., Kamenev, Alex
We consider thermodynamic and transport properties of a long granular array with strongly connected grains (inter-grain conductance g>>1.) We find that the system exhibits activated behavior of...
Quantum critical fluctuations in disordered d-wave superconductors (2002)
Meyer, Julia S., Gornyi, Igor V., Altland, Alexander
Quasiparticles in the cuprates appear to be subject to anomalously strong inelastic damping mechanisms. To explain the phenomenon, Sachdev and collaborators recently proposed to couple the system to...
Huckestein, Bodo, Altland, Alexander
We present a numerical study of the quasi-particle density of states (DoS) of two-dimensional d-wave superconductors in the presence of disorder, focusing on the influence of the range of the...
Spectral and Transport Properties of d-Wave Superconductors With Strong Impurities (2001)
One of the remarkable features of disordered d-wave superconductors is strong sensitivity of long range properties to the microscopic realization of the disorder potential. Particularly rich...
Magnetotunneling spectroscopy of mesoscopic correlations in two-dimensional electron systems (2001)
Meyer, Julia S., Altland, Alexander, Janssen, Martin
An approach to experimentally exploring electronic correlation functions in mesoscopic regimes is proposed. The idea is to monitor the mesoscopic fluctuations of a tunneling current flowing between...
Meyer, Julia S., Altland, Alexander, Altshuler, B. L.
We analyze the magnetoconductance of two-dimensional electron and hole gases (2DEGs) subject to a parallel magnetic field. It is shown that, for confining potential wells which are symmetric with...
Spectral and Transport Properties of Quantum Wires with Bond Disorder (2001)
Altland, Alexander, Merkt, Rainer
Systems with bond disorder are defined through lattice Hamiltonians that are of pure nearest neighbour hopping type, i.e. do not contain on-site contributions. Previous analyses based on the...
Taras-Semchuk, D., Altland, Alexander
We discuss a number of basic physical mechanisms relevant to the formation of the proximity effect in superconductor/normal metal (SN) systems. Specifically, we review why the proximity effect...
Quasi-Particle density of states of disordered d-wave superconductors (2000)
Huckestein, Bodo, Altland, Alexander
We present a numerical study of the quasi-particle density of states (DoS) of two-dimensional d-wave superconductors in the presence of smooth disorder. We find power law scaling of the DoS with an...
Wigner-Dyson Statistics from the Keldysh Sigma-Model (2000)
Altland, Alexander, Kamenev, Alex
The level statistics of disordered metallic grains with broken time reversal invariance is obtained from a saddle point analysis of the Keldysh nonlinear sigma-model.
Theories of Low-Energy Quasi-Particle States in Disordered d-Wave Superconductors (2000)
Altland, Alexander, Simons, B. D., Zirnbauer, M. R.
The physics of low-energy quasi-particle excitations in disordered d-wave superconductors is a subject of ongoing intensive research. Over the last decade, a variety of conceptually and...
Quantum interference and Coulomb interaction in arrays of tunnel junctions (2000)
Beloborodov, I. S., Efetov, K. B., Altland, Alexander, Hekking, F. W. J.
We study the electronic properties of an array of small metallic grains connected by tunnel junctions. Such an array serves as a model for a granular metal. Previous theoretical studies of junction...
Effective Field Theory of the Random Flux Model (1999)
Altland, Alexander, Simons, B D
The random flux model (defined here as a model of lattice fermions hopping under the influence of maximally random link disorder) is analysed field theoretically. It is shown that the long range...
Magnetotunneling as a Probe of Luttinger-Liquid Behavior (1999)
Altland, Alexander, Barnes, C. H. W., Hekking, F. W. J., Schofield, A. J.
A novel method for detecting Luttinger-liquid behavior is proposed. The idea is to measure the tunneling conductance between a quantum wire and a parallel two-dimensional electron system as a...
Competition between zero bias anomaly and proximity effect in disordered systems (1999)
Oreg, Yuval, Brouwer, P. W., Simons, B. D., Altland, Alexander
We investigate the suppression of the proximity effect in mesoscopic normal metal/superconductor systems induced by Coulomb interaction. We identify and elucidate the mechanism by which disorder...
Field Theory of the Random Flux Model (1998)
Altland, Alexander, Simons, B D
The long-range properties of the random flux model (lattice fermions hopping under the influence of maximally random link disorder) are shown to be described by a supersymmetric field theory of...
Field Theory of Mesoscopic Fluctuations in Superconductor/Normal-Metal Systems (1998)
Altland, Alexander, Simons, B. D., Taras-Semchuk, D.
Thermodynamic and transport properties of mesoscopic conductors are strongly influenced by the proximity of a superconductor: An interplay between the large scale quantum coherent wave functions in...
Hecker, Klaus, Hegger, Helmut, Altland, Alexander, Fiegle, Klaus
In their comment cond-mat/9710285 [Phys. Rev. Lett. 80, 5024 (1998)] den Hartog and van Wees (HW) raise objections against our analysis of the experimental data presented in cond-mat/9708162 [Phys....
Random Dirac Fermions and Non-Hermitian Quantum Mechanics (1997)
Mudry, Christopher, Simons, B. D., Altland, Alexander
We study the influence of a strong imaginary vector potential on the quantum mechanics of particles confined to a two-dimensional plane and propagating in a random impurity potential. We show that...
Field Theory of Mesoscopic Fluctuations in Superconductor/Normal-Metal Systems (1997)
Altland, Alexander, Simons, B D, Taras-Semchuk, D
Thermodynamic and transport properties of normal disordered conductors are strongly influenced by the proximity of a superconductor. A cooperation between mesoscopic coherence and Andreev scattering...
Conductance fluctuations in mesoscopic normal-metal/superconductor samples (1997)
Hecker, Klaus, Hegger, Helmut, Altland, Alexander, Fiegle, Klaus
We study the magnetoconductance fluctuations of mesoscopic normal-metal/superconductor (NS) samples consisting of a gold-wire in contact with a niobium film. The magnetic field strength is varied...
Perturbation Theory for the Rosenzweig-Porter Matrix Model (1997)
Altland, Alexander, Janssen, Martin, Shapiro, Boris
We study an ensemble of random matrices (the Rosenzweig-Porter model) which, in contrast to the standard Gaussian ensemble, is not invariant under changes of basis. We show that a rather complete...
Altland, Alexander, Zirnbauer, Martin R.
In a recent comment [cond-mat/9703106] Casati, Izrailev and Sokolov claim that our analysis of the quantum kicked rotor [Phys. Rev. Lett. 77, 4536 (1996), chao-dyn/9609014] seems to miss an important...
Field theory of the quantum kicked rotor (1996)
Altland, Alexander, Zirnbauer, Martin R.
The quantum kicked rotor is investigated by field theoretical methods. It is shown that the effective theory describing the long wave length physics of the system is precisely the supersymmetric...
Novel Symmetry Classes in Mesoscopic Normal-Superconducting Hybrid Structures (1996)
Altland, Alexander, Zirnbauer, Martin R.
Normal-conducting mesoscopic systems in contact with a superconductor are classified by the symmetry operations of time reversal and rotation of the electron's spin. Four symmetry classes are...
What is the Thouless Energy for Ballistic Systems? (1995)
Altland, Alexander, Gefen, Yuval, Montambaux, Gilles
The Thouless energy, $\Ec$ characterizes numerous quantities associated with sensitivity to boundary conditions in diffusive mesoscopic conductors. What happens to these quantities if the disorder...
Random Matrix Theory of a Chaotic Andreev Quantum Dot (1995)
Altland, Alexander, Zirnbauer, Martin R.
A new universality class distinct from the standard Wigner-Dyson ones is identified. This class is realized by putting a metallic quantum dot in contact with a superconductor, while applying a...
Zur streutheoretischen Untersuchung mesoskopischer Systeme. (1990)
Heidelberg, Univ., Diss., 1991.