Time-resolved pure spin fractionalization and spin-charge separation in helical Luttinger liquid based devices

We analyze the time evolution of spin-polarized electron wave packets injected into the edge states of a two-dimensional topological insulator. In the presence of electron interactions, the system is described as a helical Luttinger liquid and injected electrons fractionalize. However, because of the presence of metallic detectors, no evidences of fractionalization are encoded in dc measurements, and in this regime the system do not show deviations from its non-interacting behavior. Nevertheless, we show that the helical Luttinger liquid nature emerges in the transient dynamics, where signatures of charge/spin fractionalization can be clearly identified.

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“…This implies that, in a helical liquid, fractionalization manifests both in the charge and in the spin sector [36,47,49].…”

Section: Equation Of Motionmentioning

confidence: 99%

Transient dynamics of spin-polarized injection in helical Luttinger liquids

Calzona

Carrega

Dolcetto

et al. 2015

Physica E: Low-dimensional Systems and Nanostructures

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“…In the context of interacting 1D systems, it is well established that their low-energy equilibrium properties are described by the Luttinger liquid (LL) model [30][31][32]. They exhibit peculiar effects stemming from their non-Fermi liquid nature due to inter-particle interactions, such as charge and spin fractionalization [19,20,[32][33][34][35][36][37][38][39][40][41][42]. In recent years the LL model has also been proven to be a very powerful tool for studying the dynamics of 1D systems after a quench of the interaction strength.…”

Section: Introductionmentioning

confidence: 99%

Quench-induced entanglement and relaxation dynamics in Luttinger liquids

et al. 2017

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We investigate the time evolution towards the asymptotic steady state of a one dimensional interacting system after a quantum quench. We show that at finite times the latter induces entanglement between right-and left-moving density excitations, encoded in their cross-correlators, which vanishes in the long-time limit. This behavior results in a universal time-decay ∝ t −2 of the system spectral properties, in addition to non-universal power-law contributions typical of Luttinger liquids. Importantly, we argue that the presence of quench-induced entanglement clearly emerges in transport properties, such as charge and energy currents injected in the system from a biased probe, and determines their long-time dynamics. In particular, the energy fractionalization phenomenon turns out to be a promising platform to observe the universal power-law decay ∝ t −2 induced by entanglement and represents a novel way to study the corresponding relaxation mechanism.

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“…The celebrated Fermi liquid theory dramatically fails and intriguing phenomena appear, such as the fractionalization of the charge [3][4][5][6][7] and the spin [7][8][9][10][11] degrees of freedom. Here, an electron injected into an interacting system splits up, originating two collective excitations that carry a fraction of the electron charge and spin.…”

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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Time-resolved pure spin fractionalization and spin-charge separation in helical Luttinger liquid based devices

Cited by 31 publications

References 54 publications

Transient dynamics of spin-polarized injection in helical Luttinger liquids

Transient dynamics of spin-polarized injection in helical Luttinger liquids

Quench-induced entanglement and relaxation dynamics in Luttinger liquids

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

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