Experimental realization of a relativistic harmonic oscillator. (20th June 2018)

• Record Type: Journal Article
• Authors: Fujiwara, Kurt M; Geiger, Zachary A; Singh, Kevin; Senaratne, Ruwan; Rajagopal, Shankari V; Lipatov, Mikhail; Shimasaki, Toshihiko; Weld, David M
• Is Part Of: New journal of physics. Volume 20:Number 6(2018:Jun.)
• Publication Date: 2018-06-20
• Subjects: Bose–Einstein condensates -- relativity -- optical lattices -- quantum dynamics; Physics -- Periodicals; Physics; Periodicals; 530.05
• DOI: 10.1088/1367-2630/aacb5a
• Languages: English
• ISSNs: 1367-2630

Abstract

Abstract: We report the experimental study of a harmonic oscillator in the relativistic regime. The oscillator is composed of Bose-condensed lithium atoms in the third band of an optical lattice, which have an energy–momentum relation nearly identical to that of a massive relativistic particle, with an effective mass reduced below the bare value and a greatly reduced effective speed of light. Imaging the shape of oscillator trajectories at velocities up to 98% of the effective speed of light reveals a crossover from sinusoidal to nearly photon-like propagation. The existence of a maximum velocity causes the measured period of oscillations to increase with energy; our measurements reveal beyond-leading-order contributions to this relativistic anharmonicity. We observe an intrinsic relativistic dephasing of oscillator ensembles, and a monopole oscillation with exactly the opposite phase of that predicted for non-relativistic harmonic motion. All observed dynamics are in quantitative agreement with longstanding but hitherto-untested relativistic predictions.