Rotating wave approximation: systematic expansion and application to coupled spin pairs

Thimmel, B.; Nalbach, P.; Terzidis, O.

doi:10.1007/s100510050758

Cited by 26 publications

(21 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therein, they employed, as typically done, the rotating wave approximation (RWA). For harmonically driven systems the RWA coincides with the lowest order of a corresponding Magnus expansion [4,13], thus, justifying it for small driving strength. However, it is unclear how well the RWA performs for chirped driving or how to determine corrections as the Bloch-Siegert shift [14] at strong driving.…”

Section: Introductionsupporting

confidence: 52%

See 1 more Smart Citation

Magnus expansion for a chirped quantum two-level system

Nalbach

Leyton

2018

Phys. Rev. A

Self Cite

View full text Add to dashboard Cite

We derive a Magnus expansion for a frequency chirped quantum two-level system. We obtain a time-independent effective Hamiltonian which generates a stroboscopic time evolution. At lowest order the according dynamics is identical to results from using a rotating wave approximation. We determine, furthermore, also the next higher order corrections within our expansion scheme in correspondence to the Bloch-Siegert shifts for harmonically driven systems. Importantly, our scheme can be extended to more complicated systems, i.e. even many-body systems.

show abstract

Section: Introductionsupporting

confidence: 52%

“…The usually employed RWA discards all remaining oscilatory time dependent terms in (2). Although at first glance a rather uncontrolled approximation, it coincides with the lowest order terms in the Magnus series expansion in η/ω 0 and δ 0 /ω 0 for harmonic driving [4,13]. For a chirped TLS this justification does not hold.…”

Section: Frequency Chirped Tlsmentioning

confidence: 83%

Magnus expansion for a chirped quantum two-level system

Nalbach

Leyton

2018

Phys. Rev. A

Self Cite

View full text Add to dashboard Cite

show abstract

“…For driven TLS, corrections beyond RWA and in terms of Bloch-Siegert shift [15] have been discussed by Grifoni and Hanggi [16]. The corrections to RWA can be formulated as a systematic expansion in terms of the ratio of Rabi frequency to the field frequency [17]. In case of two coupled TLS, there exists a parameter regime where leading order term in the expansion vanishes rendering the next higher order term to be significant [17].…”

Section: The Modelmentioning

confidence: 99%

Decay dynamics in a strongly driven atom–molecule coupled system

Rakshit¹,

Ghosh²,

Deb³

2014

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

Abstract. Within the framework of master equation, we study decay dynamics of an atommolecule system strongly coupled by two photoassociation lasers. Summing over the infinite number of electromagnetic vacuum modes that are coupled to the system, we obtain an integrodifferential master equation for the the system's reduced density matrix. We use this equation to describe correlated spontaneous emission from a pair of electronically excited diatomic ro-vibrational states. The temporal evolution of emitted radiation intensity shows quantum beats that result from the laser-induced coherence between the two excited states. The phase difference between the two driving fields is found to significantly affect the decay dynamics and the beats. Our results demonstrate the possibility to control decay and decoherence in the system by tuning the relative intensity and the phase between the two lasers. We further show that, if the ground-state continuum has a shape resonance at a low energy, then the quantum beats show two distinctive time scales of oscillations in the strong coupling regime. One of the time scales originates from the energy gap between the two excited states while the other time scale corresponds to the collision energy at which free-bound Franck-Condon overlap is resonantly peaked due to the shape resonance.

show abstract

“…Similar mappings of time-dependent problems onto effective timeindependent models are available in the literature. [36][37][38][39][40] Here we transform the full Hamiltonian, Eq. (1), into the rotating frame of the field 41, 42…”

Section: Model and Methodsmentioning

confidence: 99%

Coherently controlled molecular junctions

Peskin

Galperin

2012

The Journal of Chemical Physics

View full text Add to dashboard Cite

Within a generic model, we discuss the possibility of coherent control of charge fluxes in unbiased molecular junctions. The control is induced by resonances between the Rabi frequency due to a pumping laser field and internal characteristic frequencies of pre-designed molecular donor-bridge-acceptor complexes. Two models are considered: a coherently controlled molecular charge pump and a molecular switch. The study generalizes previous consideration of light induced current [M. Galperin and A. Nitzan, Phys. Rev. Lett. 95, 206802 (2005)] and of a molecular electron pump [R. Volkovich and U. Peskin, Phys. Rev. B 83, 033403 (2011)] and accounts for the coherently driven charge transport in an unbiased molecular junction with symmetric coupling to leads. Numerical examples demonstrate the feasibility of the control mechanism for realistic junctions parameters.

show abstract

Rotating wave approximation: systematic expansion and application to coupled spin pairs

Cited by 26 publications

References 13 publications

Magnus expansion for a chirped quantum two-level system

Magnus expansion for a chirped quantum two-level system

Decay dynamics in a strongly driven atom–molecule coupled system

Coherently controlled molecular junctions

Contact Info

Product

Resources

About