Berlin 2024 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 13: Poster I

HL 13.2: Poster

Monday, March 18, 2024, 15:00–18:00, Poster E

Quantifying quantum coherence in multi-mode polariton condensates — •Maximilian Nürmberger, Franziska Barkhausen, Xuekai Ma, Jan Sperling, and Stefan Schumacher — Department of Physics, CeOPP, and PhoQS, Paderborn University, Germany

One of the main challenges when engineering future quantum devices based on light-matter interaction is achieving resourceful and long-term coherent quantum states. We theoretically investigate quantum features of a polariton system and quantify the amount of quantum coherence that results from the quantum superposition of Fock states, constituting a measure of the resourcefulness for modern quantum protocols. We use phase-space quasi probability distributions of macroscopic polariton states to quantify changes in the quantum coherence beyond the condensation threshold [1,3] and calculate the time evolution using a regularized Glauber-Sudarshan representation [2,3]. Furthermore, we include the polarization degree of freedom and expand our calculations into orbital angular momentum (OAM) space to investigate the quantum coherence of multi-mode systems. In doing so we can calculate the quantum coherence of different vortex states in polariton condensates. We theoretically study vortices excited non-resonantly in an optically induced ring-shaped potential. By introducing a resonant control pulse in either polarization component, we can switch between different vortex-states [4]. [1] C. Lüders et al., PRX Quantum 2, 030320 (2021). [2] C. Lüders et al., Phys. Rev. Lett. 130, 113601 (2023). [3] C. Lüders et al., Opt. Mater. Express 13, 2997-3035 (2023). [4] M. Pukrop et al., Phys. Rev. B 101, 205301 (2020).

Keywords: quantum coherence; polariton condensate; vortices; polariton; orbital angular momentum