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D. A. Saltykova

Publications and source records attributed to D. A. Saltykova.

4 recordsLinked to original sources

Acoustic spin resonance in polariton condensates

We theoretically investigate acoustic spin resonance in a spatially homogeneous spinor polariton condensate. A longitudinal acoustic wave generates a time-periodic strain-induced effective magnetic field acting on the condensate pseudospin. When this field is transverse to the static in-plane linear-polarization splitting, it resonantly drives polarization oscillations. We show that spin-dependent interactions shift the resonance and produce nonlinear line shapes, while gain, reservoir dynamics, and spin relaxation make the response dissipative and history-dependent, producing amplitude hysteresis. In the presence of lifetime anisotropy, the condensate can develop a bifurcated stationary state with finite circular polarization, and a resonant acoustic drive can switch between the corresponding out-of-plane branches. A Zeeman splitting provides an additional conservative knob for tuning the resonance frequency. Our results identify coherent acoustic driving as a route to resonant, nonlinear, and switchable control of polariton pseudospin dynamics.

cond-mat.mes-hall↗

Ground-State Selection by Pure Energy Relaxation in Polariton Condensates

We study nonequilibrium mode selection in dissipative exciton-polariton condensates incoherently pumped through an excitonic reservoir in the presence of pure energy relaxation. For a confined system in which a vortex mode is selected at threshold, we show that energy relaxation qualitatively changes the condensation scenario: as the pump increases, the asymptotic state evolves from a vortex condensate to a rotating mixed state and then to a ground-state condensate. Pure energy relaxation thus destabilizes condensation into excited states and promotes ground-state selection.

cond-mat.mes-hall↗

Quantum hydrodynamics of a polariton fluid: pure energy relaxation terms

Cavity polaritons, hybrid half-light half-matter excitations in quantum microcavities in the strong-coupling regime demonstrate clear signatures of quantum collective behavior, such as analogues of Bose-Einstein condensate and superfluidity at remarkably high temperatures. The analysis of the formation of these states demands an account of the relaxation processes in the system. Although there are well-established approaches for the description of some of them, such as finite lifetime polariton, an external optical pump, and coupling with an incoherent excitonic reservoir, the treatment of pure energy relaxation in a polariton fluid still remains a puzzle. Here, based on the quantum hydrodynamics approach, we derive the corresponding equations where the energy relaxation term appears naturally. We analyze in detail how it affects the dynamics of polariton droplets and the dispersion of elementary excitations of a uniform polariton condensate. Although we focus on the case of cavity polaritons, our approach can be applied to other cases of bosonic condensates, where the processes of energy relaxation play an important role.

cond-mat.mes-hall↗

Spin relaxation in a polariton fluid: quantum hydrodynamic approach

Cavity polaritons, the elementary excitations appearing in quantum microcavities in the strong-coupling regime, reveal clear signatures of quantum collective behavior. The combination of unique spin structure and strong nonlinear response opens the possibility of direct experimental observation of a plethora of nontrivial optical polarization phenomena. Spin relaxation processes are of crucial importance here. However, a mathematical formalism for their coherent description is still absent. In the present paper, based on the quantum hydrodynamics approach for a two-component liquid, we derive the set of the corresponding equations where both energy and spin relaxation terms appear naturally. We analyze in detail how these terms affect the dynamics of spinor polariton droplets in the external magnetic field and the dispersion of elementary excitations of a uniform polariton condensate. Although we focus on the case of cavity polaritons, our approach can be applied to other cases of spinor bosonic condensates, where the processes of spin relaxation play a major role.

cond-mat.mes-hall↗