Population transfer via a dissipative structural continuum

Abstract

We propose a model to study quantum population transfer via a structural continuum. The model is composed of two spins which are coupled to two bosonic modes separately by two controled pulses, and the two bosonic modes are coupled to a common structural continuum. We show that efficient population transfer can be achieved between the two spins by using a multi-level stimulated Raman adiabatic passage (STIRAP) across the continuum, which we refer to as straddle STIRAP via continuum. We also consider the stability of this model against different control parameters and show that efficient population transfer can be achieved even in presence a moderate dissipation.

Population transfer under local dephasing

“…for all t. Substituting Eqs. (22,24,26) back into Eqs. (20), and assuming ρ +d = a + ib with a(t) and b(t) real functions, we get the following closed set of equations for ρ dd , a, b…”

“…We can see that our model remains the same if the intermediate spin is replaced by a dephasing bosonic mode and rotating wave approximation is applied to the spin-boson couplings, where the intermediate bosonic mode may be physically implemented using a cavity as the "flying qubit". It is also possible to generalize the intermediate state in our model as a chain of spins as in straddle STI-RAP [29,30], or a bosonic continuum [24,25] under dephasing. Now using the mapping…”

“…STIRAP has important advantages that it is robust against to the variations of the experimental conditions [16], and against to the decaying of the intermediate state [17][18][19]. STIRAP via multiple intermediate states has also been considered [20], as well as generalizations to intermediate state as a continuum [19,[21][22][23] and a lossy continuum [24], where it is shown that significant partial population transfer can still be achieved. Recently, STIRAP via a thermal state or a thermal continuum has been studied, showing that the efficiency of population transfer will be reduced significantly in this case [25].…”

Optimized pulses for population transfer via laser induced continuum structures

“…In these works, the population transfer is accomplished using a counterintuitive STIRAP pulse sequence [15][16][17][18], which in most cases consists of two delayed Gaussian pulses. The method has been experimentally demonstrated in helium atoms [19,20], while other interesting applications include coherence effects [21,22], like population trapping and electromagnetically induced transparency, photonics [23], specifically optical analogs for light waves propagating in waveguide-based photonic structures [24,25], and qubits coupled through a bosonic structural continuum [26] or the quasi-continuous spectrum of modes in a waveguide [27]. There is actually a plethora of systems where the population transfer between two bound states coupled via a continuum could be useful [28].…”

Electronic controllable broadband and robust terahertz surface plasmon-polaritons switch based on hybrid ITO waveguide coupler

“…Most recently, there are two remarkable papers which proposed broadband and robust THz SPPs waveguide coupler based on coherent quantum control [10,11]. The technique of coherent quantum control can be broadly used in many-body physics [12], waveguide coupler [13] and graphene SPPs waveguide coupler [14]. Due to the robustness of coherent quantum control, the especial curved SPPs waveguide coupler [10,11] can completely transfer the energy of SPPs from input to output waveguide with wide working band and insensitivity to the perturbations of geometrical parameters.…”