Related papers: Population trapping in three-state quantum loops r…
A full quantum treatment of coherent population trapping (CPT) is given for a system of resonantly coupled atoms and electromagnetic field. We develop a regular analytical method of the construction of generalized dark states (GDS). It…
We show that high squeezing and entanglement can be generated at the output of a cavity containing atoms interacting with two fields in a Coherent Population Trapping situation, on account of a non-linear Faraday effect experienced by the…
Trapped state definition for 3-level atoms in Lambda configuration, is a very restrictive one, and for the case of unpolarized beams, this definition no longer holds.We introduce a more general definition by using a reference frame rotating…
We present theoretical and experimental results of coherent population trapping spectra on a multi-level $^{40}$Ca$^+$-type configuration, adding a third beam to the standard two-laser $\Lambda$ system to avoid undesired optical pumping. We…
We show that the physical mechanism of population transfer in a 3-level system with a closed loop of coherent couplings (loop-STIRAP) is not equivalent to an adiabatic rotation of the dark-state of the Hamiltonian but coresponds to a…
We analyzed the efficiency of coherent population trapping (CPT) in a superposition of the ground states of three-level atoms under the influence of the decoherence process induced by a broadband thermal field. We showed that in a single…
Physical systems usually exhibit quantum behavior, such as superpositions and entanglement, only when they are sufficiently decoupled from a lossy environment. Paradoxically, a specially engineered interaction with the environment can…
We study numerically the development of chimera states in networks of nonlocally coupled oscillators whose limit cycles emerge from a Hopf bifurcation. This dynamical system is inspired from population dynamics and consists of three…
As was shown in quant-ph/0405028, the state of a tunneling particle can be uniquely presented as a coherent superposition of two states to describe alternative sub-processes, transmission and reflection. In this paper, on the basis of the…
Resonance trapping appears in open many-particle quantum systems at high level density when the coupling to the continuum of decay channels reaches a critical strength. Here a reorganization of the system takes place and a separation of…
Many-particle confinement (localization) is studied for a 1D system of spinless fermions with nearest-neighbor hopping and interaction, or equivalently, for an anisotropic Heisenberg spin-1/2 chain. This system is frequently used to model…
The population dynamics of a trapped Bose-Einstein condensate, subject to the action of an oscillatory field, is studied. This field produces a modulation of the trapping potential with the frequency close to the transition frequency…
We study a quantum trimer of coupled two-level systems beyond the single-excitation sector, where the coherent coupling constants are ornamented by a complex phase. Accounting for losses and gain in an open quantum systems approach, we show…
A quantum computing system is typically represented by a set of non-interacting (local) two-state systems - qubits. Many physical systems can naturally have more accessible states, both local and non-local. We show that the resulting…
We show theoretically that by applying a bichromatic electromagnetic field, the dressed states of a monochromatically driven two-level atom can be pumped into a coherent superposition termed as dressed-state coherent population trapping.…
We study a double quantum dot system coherently coupled to an electromagnetic resonator. A current through the dot system can create a population inversion in the dot levels and, within a narrow resonance window, a lasing state in the…
We study a triangular network of three populations of coupled phase oscillators with identical frequencies. The populations interact nonlocally, in the sense that all oscillators are coupled to one another, but more weakly to those in…
We theoretically investigate how population can be trapped in the excited doublet in presence of vacuum-induced coherence (VIC). We employ delayed pulses to transfer population from a metastable state to the excited states. Subsequently,…
Multistability, the coexistence of multiple stable states, is a cornerstone of nonlinear dynamical systems, governing their equilibrium, tunability, and emergent complexity. Recently, the concept of hidden multistability, where certain…
A population transfer based on adiabatic evolutions in a three-state system undergoing an avoided crossing is considered. The efficiency of the process is analyzed in connection with the relevant parameters, bringing to light an important…