Controlling the Sign of Magnetoconductance in Andreev Quantum Dots (2009)
Whitney, Robert S., Jacquod, Ph.
We construct a trajectory-based semiclassical theory of transport through a ballistic quantum dot coupled to a superconductor. We show that the leading-order quantum correction to the two-terminal...
We briefly review three ways that environmental noise can slow-down (or speed-up) quantum transitions; (i) Lamb shifts, (ii) over-damping and (iii) orthogonality catastrophe. We compare them with the...
Semiclassical transport in nearly symmetric quantum dots I: symmetry-breaking in the dot (2009)
Whitney, Robert S., Schomerus, Henning, Kopp, Marten
We apply the semiclassical theory of transport to quantum dots with exact and approximate spatial symmetries; left-right mirror symmetry, up-down mirror symmetry, inversion symmetry or four-fold...
Whitney, Robert S., Schomerus, Henning, Kopp, Marten
In this work - the second of a pair of articles - we consider transport through spatially symmetric quantum dots with leads whose widths or positions do not obey the spatial symmetry. We use the...
Symmetry causes a huge conductance peak in double quantum dots (2009)
Whitney, Robert S., Marconcini, P., Macucci, M.
We predict a huge interference effect contributing to the conductance through large ultra-clean quantum dots of chaotic shape. When a double-dot structure is made such that the dots are the...
Environmental suppression of non-adiabaticity: observing a Berry phase alone (2008)
We consider a two-level system coupled to a high-frequency environment (quantum or classical), when the direction of the coupling axis changes with time. We show that the system's instantaneous...
Staying positive: going beyond Lindblad with perturbative master equations (2007)
The perturbative master equation (Bloch-Redfield) is extensively used to study dissipative quantum mechanics - particularly for qubits - despite the 25 year old criticism that it violates positivity...
Dephasing in quantum chaotic transport: a semiclassical approach (2007)
Whitney, Robert S., Jacquod, Philippe, Petitjean, Cyril
We investigate the effect of dephasing/decoherence on quantum transport through open chaotic ballistic conductors in the semiclassical limit of small Fermi wavelength to system size ratio,...
Shot-noise of quantum chaotic systems in the classical limit (2007)
Semiclassical methods can now explain many mesoscopic effects (shot-noise, conductance fluctuations, etc) in clean chaotic systems, such as chaotic quantum dots. In the deep classical limit...
Towards a dephasing diode: asymmetric and geometric dephasing (2007)
Whitney, Robert S., Shnirman, Alexander, Gefen, Yuval
We study the effect of a noisy environment on spin and charge transport in ballistic quantum wires with spin-orbit coupling (Rashba coupling). We find that the wire then acts as a ``dephasing...
We add simple tunnelling effects and ray-splitting into the recent trajectory-based semiclassical theory of quantum chaotic transport. We use this to derive the weak-localization correction to...
Dephasing in the semiclassical limit is system-dependent (2006)
Petitjean, Cyril, Jacquod, Philippe, Whitney, Robert S.
We investigate dephasing in open quantum chaotic systems in the limit of large system size to Fermi wavelength ratio, $L/\lambda_F >> 1$. We semiclassically calculate the weak localization correction...
Jacquod, Ph., Whitney, Robert S.
We investigate transport properties of quantized chaotic systems in the short wavelength limit. We focus on non-coherent quantities such as the Drude conductance, its sample-to-sample fluctuations,...
Shot noise in semiclassical chaotic cavities (2005)
Whitney, Robert S., Jacquod, Philippe
We construct a trajectory-based semiclassical theory of shot noise in clean chaotic cavities. In the universal regime of vanishing Ehrenfest time $\tE$, we reproduce the random matrix theory result,...
Semiclassical Theory of Quantum Chaotic Transport: Phase-Space Splitting (2005)
Jacquod, Ph., Whitney, Robert S.
This paper is withdrawn. While almost all findings reported here remain valid, some of our comments on the fate of weak localization corrections to the conductance in the deep semiclassical limit are...
Suppression of Shot-Noise in Quantum Cavities: Chaos vs. Disorder (2005)
Jacquod, Philippe, Whitney, Robert S.
We investigate the behavior of the shot-noise power through quantum mechanical cavities in the semiclassical limit of small electronic wavelength. In the absence of impurity scattering, the Fano...
Microscopic Theory for the Quantum to Classical Crossover in Chaotic Transport (2004)
Whitney, Robert S., Jacquod, Ph.
We present a semiclassical theory for the scattering matrix ${\cal S}$ of a chaotic ballistic cavity at finite Ehrenfest time. Using a phase-space representation coupled with a multi-bounce...
Geometric nature of the environment-induced Berry phase and geometric dephasing (2004)
Whitney, Robert S., Makhlin, Yuriy, Shnirman, Alexander, Gefen, Yuval
We investigate the geometric phase or Berry phase (BP) acquired by a spin-half which is both subject to a slowly varying magnetic field and weakly-coupled to a dissipative environment (either quantum...
Berry phase with environment: classical versus quantum (2004)
Whitney, Robert S., Makhlin, Yuriy, Shnirman, Alexander, Gefen, Yuval
We discuss the concept of the Berry phase in a dissipative system. We show that one can identify a Berry phase in a weakly-dissipative system and find the respective correction to this quantity,...
Berry phase in a non-isolated system (2002)
Whitney, Robert S., Gefen, Yuval
We investigate the effect of the environment on a Berry phase measurement involving a spin-half. We model the spin+environment using a biased spin-boson Hamiltonian with a time-dependent magnetic...
Form factor for a family of quantum graphs: An expansion to third order (2002)
Berkolaiko, Gregory, Schanz, Holger, Whitney, Robert S.
For certain types of quantum graphs we show that the random-matrix form factor can be recovered to at least third order in the scaled time $\tau$ from periodic-orbit theory. We consider the...
The Leading Off-Diagonal Correction to the Form Factor of Large Graphs (2001)
Berkolaiko, Gregory, Schanz, Holger, Whitney, Robert S.
Using periodic-orbit theory beyond the diagonal approximation we investigate the form factor, $K(\tau)$, of a generic quantum graph with mixing classical dynamics and time-reversal symmetry. We...
Does Berry phase exist for a system coupled to its environment? (2001)
Whitney, Robert S., Gefen, Yuval
Berry phase was originally defined for systems whose states are separated by finite energy gaps. One might naively expect that a system without a gap cannot have a Berry phase. Despite this we ask...
Can the trace formula describe weak localisation? (1999)
Whitney, Robert S., Lerner, Igor V., Smith, Robert A.
We attempt to systematically derive perturbative quantum corrections to the Berry diagonal approximation of the two-level correlation function (TLCF) for chaotic systems. To this end, we develop a...