Ultrafast control of inelastic tunneling in a double semiconductor quantum well

Schüler, Michael; Pavlyukh, Y.; Berakdar, J.

doi:10.1063/1.3505502

Cited by 4 publications

(5 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…20a,b evidencing that the localization induced by a single HCP is satisfactorily robust, at least for the type of scattering events taken into account. Considering another type of scattering yielded also similar findings [244]. Clearly if the coupling to the vibrating impurity is very strong the localization becomes ineffective (cf.…”

Section: Persistent Localization In Presence Of Relaxationsupporting

confidence: 62%

“…Hence the strongest destruction of the electron localization due to the impurity coupling is expected when the impurity is in the middle of one of the wells where the electronic wave packet is localized. In that case the localization scheme (Section 4.3.3) needs to be adjusted [244], but nevertheless is still possible; the point here is then whether it is still sustainable. As detailed in Ref.…”

Section: Persistent Localization In Presence Of Relaxationmentioning

confidence: 99%

“…As detailed in Ref. [244] the stability of the localized wave packet is achievable with an adjusted pulse sequence or by applying a con- stant electric field oriented in the x-direction. A typical result is shown in Fig.…”

Section: Persistent Localization In Presence Of Relaxationmentioning

confidence: 99%

“…Time is measured in units of T0 = 2π /(∆E) where ∆E is the energy splitting between the two lowest energy levels (in the presence of the vibrational modes). Panels correspond to different values of the scaled coupling parameter γ = 2V 0 / ω ph : (a) γ = 0, (b) γ = 0.6, and(c) γ = 1 (adapted from Ref [244]…”

mentioning

confidence: 99%

See 3 more Smart Citations

Charge and spin dynamics driven by ultrashort extreme broadband pulses: a theory perspective

Moskalenko,

Zhu,

Berakdar

2016

Preprint

Self Cite

View full text Add to dashboard Cite

This article gives an overview on recent theoretical progress in controlling the charge and spin dynamics in low-dimensional electronic systems by means of ultrashort and ultrabroadband electromagnetic pulses.A particular focus is put on sub-cycle and single-cycle pulses and their utilization for coherent control. The discussion is mostly limited to cases where the pulse duration is shorter than the characteristic time scales associated with the involved spectral features of the excitations. The relevant current theoretical knowledge is presented in a coherent, pedagogic manner. We work out that the pulse action amounts in essence to a quantum map between the quantum states of the system at an appropriately chosen time moment during the pulse. The influence of a particular pulse shape on the post-pulse dynamics is reduced to several integral parameters entering the expression for the quantum map. The validity range of this reduction scheme for different strengths of the driving fields is established and discussed for particular nanostructures. Acting with a periodic pulse sequence, it is shown how the system can be steered to and largely maintained in predefined states. The conditions for this nonequilibrium sustainability are worked out by means of geometric phases, which are identified as the appropriate quantities to indicate quasistationarity of periodically driven quantum systems. Demonstrations are presented for the control of the charge, spin, and valley degrees of freedom in nanostructures on picosecond and subpicosecond time scales. The theory is illustrated with several applications to one-dimensional semiconductor quantum wires and superlattices, double quantum dots, semiconductor and graphene quantum rings. In the case of a periodic pulsed driving the influence of the relaxation and decoherence processes is included by utilizing the density matrix approach. The integrated and time-dependent spectra of the light emitted from the driven system deliver information on its spin-dependent dynamics. We review examples of such spectra of photons emitted from pulse-driven nanostructures as well as a possibility to characterize and control the light polarization on an ultrafast time scale. Furthermore, we consider the response of strongly correlated systems to short broadband pulses and show that this case bears a great potential to unveil high order correlations while they build up upon excitations.

show abstract

Section: Persistent Localization In Presence Of Relaxationsupporting

confidence: 62%

Section: Persistent Localization In Presence Of Relaxationmentioning

confidence: 99%

Section: Persistent Localization In Presence Of Relaxationmentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Charge and spin dynamics driven by ultrashort extreme broadband pulses: a theory perspective

Moskalenko,

Zhu,

Berakdar

2016

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…exp½ÀixF p w el ðx; tÞ with F p ¼ Ð dtE HCP ðtÞ. With appropriate amplitude and timing, w el can be driven from the delocalized ground state to one of the wells and sustained there (even in the presence of electron-vibron interaction 24 ). This implies that w(t) can almost be kept at a constant values w ¼ 0 ðP L $ 0Þ or w max ðP L $ 1Þ.…”

mentioning

confidence: 99%

Generation and coherent control of pure spin currents via terahertz pulses

Schüler

Berakdar

2014

Applied Physics Letters

Self Cite

View full text Add to dashboard Cite

We inspect the time and spin-dependent, inelastic tunneling in engineered semiconductor-based double quantum well driven by time-structured terahertz pulses. An essential ingredient is an embedded spin-active structure with vibrational modes that scatter the pulse driven carriers. Due to the different time scales of the charge and spin dynamics, the spin-dependent electron-vibron coupling may result in pure net spin current (with negligible charge current). Heating the vibrational site may affect the resulting spin current. Furthermore, by controlling the charge dynamics, the spin dynamics and the generated spin current can be manipulated and switched on and off coherently.

show abstract