Anomalous Friedel oscillations in a quasihelical quantum dot

Gambetta, F. M.; Ziani, N. Traverso; Barbarino, Simone; Cavaliere, Fabio; Sassetti, Maura

doi:10.1103/physrevb.91.235421

Cited by 24 publications

(20 citation statements)

References 67 publications

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“…One of the goals of this work is to compare the properties of our microscopic model to those of the popular LL models [26][27][28][29][30][31][32][33][34][35][36][37], specifically, the spiral LL and the helical LL. The spiral LL was first introduced by Braunecker et al [38,39] to describe a LL embedded in a lattice of nuclear spins.…”

Section: Introductionmentioning

confidence: 99%

Interaction effects in a microscopic quantum wire model with strong spin–orbit interaction

et al. 2017

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We investigate the effect of strong interactions on the spectral properties of quantum wires with strong Rashba spin-orbit interaction in a magnetic field, using a combination of Matrix Product State and bosonization techniques. Quantum wires with strong Rashba spin-orbit interaction and magnetic field exhibit a partial gap in one-half of the conducting modes. Such systems have attracted wide-spread experimental and theoretical attention due to their unusual physical properties, among which are spin-dependent transport, or a topological superconducting phase when under the proximity effect of an s-wave superconductor. As a microscopic model for the quantum wire we study an extended Hubbard model with spin-orbit interaction and Zeeman field. We obtain spin resolved spectral densities from the real-time evolution of excitations, and calculate the phase diagram. We find that interactions increase the pseudo gap at k = 0 and thus also enhance the Majorana-supporting phase and stabilize the helical spin order. Furthermore, we calculate the optical conductivity and compare it with the low energy spiral Luttinger Liquid result, obtained from field theoretical calculations. With interactions, the optical conductivity is dominated by an excotic excitation of a bound soliton-antisoliton pair known as a breather state. We visualize the oscillating motion of the breather state, which could provide the route to their experimental detection in e.g. cold atom experiments.

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Section: Introductionmentioning

confidence: 99%

Interaction effects in a microscopic quantum wire model with strong spin–orbit interaction

et al. 2017

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“…In this work, we consider the on-demand injection of a single polarized electron from a quantum dot (QD) mesoscopic capacitor into a couple of interacting helical edge states, modeled as helical Luttinger liquid (HLL) [46,[51][52][53][54][55]. Our goal is to study how the presence of e-e interactions affects the dynamics after an injection of a single electron into the edge channels of a 2DTI.…”

Section: Introductionmentioning

confidence: 99%

Time-resolved energy dynamics after single electron injection into an interacting helical liquid

et al. 2016

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The possibility of injecting a single electron into ballistic conductors is at the basis of the new field of electron quantum optics. Here, we consider a single electron injection into the helical edge channels of a topological insulator. Their counterpropagating nature and the unavoidable presence of electron-electron interactions dramatically affect the time evolution of the single wave packet. Modeling the injection process from a mesoscopic capacitor in the presence of nonlocal tunneling, we focus on the time-resolved charge and energy packet dynamics. Both quantities split up into counterpropagating contributions whose profiles are strongly affected by the interaction strength. In addition, stronger signatures are found for the injected energy, which is also affected by the finite width of the tunneling region, in contrast to what happens for the charge. Indeed, the energy flow can be controlled by tuning the injection parameters, and we demonstrate that, in the presence of nonlocal tunneling, it is possible to achieve a situation in which charge and energy flow in opposite directions.

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“…The validity of LLs as low energy theories for 1D systems of fermions, bosons and spin, has been demonstrated experimentally by means of anomalous tunneling effects 32,33 , or by observing spin-charge separation [34][35][36] . Moreover, the LL theory represents a very useful tool for the study of a wide range of 1D systems, including integer 37 and fractional 38 quantum Hall effects and two dimensional topological insulators [39][40][41][42] , weakly interacting quantum wires 32 , even in the presence of spin-orbit coupling [43][44][45][46][47][48] , carbon nanotubes 33,49,50 , eventually including electron phonon coupling 51,52 , spin chains 53,54 and, complemented with its spin incoherent version 55,56 , Wigner crystals [57][58][59][60][61][62][63] . The validity of the LL picture as a low energy theory for 1D Hamiltonians is however limited to the low energy excitations of gapless phases 29,31 .…”

Section: Introductionmentioning

confidence: 99%

Out-of-equilibrium density dynamics of a quenched fermionic system

et al. 2016

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Using a Luttinger liquid theory we investigate the time evolution of the particle density of a one-dimensional fermionic system with open boundaries and subject to a finite duration quench of the inter-particle interaction. We provide analytical and asymptotic solutions to the unitary time evolution of the system, showing that both switching on and switching off the quench ramp create light-cone perturbations in the density. The post-quench dynamics is strongly affected by the interference between these two perturbations. In particular, we find that the discrepancy between the time-dependent density and the one obtained by a generalized Gibbs ensemble picture vanishes with an oscillatory behavior as a function of the quench duration, with local minima corresponding to a perfect overlap of the two light-cone perturbations. For adiabatic quenches, we also obtain a similar behavior in the approach of the generalized Gibbs ensemble density towards the one associated with the ground state of the final Hamiltonian.

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Anomalous Friedel oscillations in a quasihelical quantum dot

Cited by 24 publications

References 67 publications

Interaction effects in a microscopic quantum wire model with strong spin–orbit interaction

Interaction effects in a microscopic quantum wire model with strong spin–orbit interaction

Time-resolved energy dynamics after single electron injection into an interacting helical liquid

Out-of-equilibrium density dynamics of a quenched fermionic system

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