Hannover 2020 – scientific programme

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Q: Fachverband Quantenoptik und Photonik

Q 13: Posters: Quantum Optics and Photonics I

Q 13.51: Poster

Monday, March 9, 2020, 16:30–18:30, Empore Lichthof

Time emergence in the coherent state basis — •Sebastian Gemsheim and Jan-Michael Rost — Max-Planck-Institut für Physik komplexer Systeme, Dresden, Deutschland

Is time fundamental or emergent? This is an old question but to date the answer remains elusive. Advocating for the latter, we examine a possible mechanism for its emergence. The time-dependent Schroedinger equation can be obtained from the time-independent Schroedinger equation for a bipartite system [1], comprised of a quantum 'clock' and a generic quantum system. Consequently, the time parameter emerges from an underlying entanglement between both subsystems.

Specifically, we take a single harmonic oscillator as the 'clock' in the coherent state basis. This allows us to explore the significance of having two degrees of freedom in the complex plane which manifests itself as a complex time parameter. We derive a one-dimensional parametrized curve in the classical limit of large 'clock' energies, i.e., a one-dimensional real-time parametrization. To be operational as a clock, the 'clock' energy must be large in order to effectively distinguish between different 'clock positions' and we quantify the achievable, energy-dependent resolution. In addition, we investigate analogies and similarities to the imaginary-time formalism, e.g., imaginary-time propagation.

[1] J. S. Briggs, S. Boonchui, and S. Khemmani, Journal of Physics A: Mathematical and Theoretical 40, 1289 (2007)