Spinorbit coupling in a hexagonal ring of pendula
Abstract
We consider the mechanical motion of a system of six macroscopic pendula which are connected with springs and arranged in a hexagonal geometry. When the springs are pretensioned, the coupling between neighbouring pendula along the longitudinal (L) and the transverse (T) directions are different: identifying the motion along the L and T directions as the two components of a spinlike degree of freedom, we theoretically and experimentally verify that the pretensioned springs result in a tunable spinorbit coupling. We elucidate the structure of such a spinorbit coupling in the extended twodimensional honeycomb lattice, making connections to physics of graphene. The experimental frequencies and the oscillation patterns of the eigenmodes for the hexagonal ring of pendula are extracted from a spectral analysis of the motion of the pendula in response to an external excitation and are found to be in good agreement with our theoretical predictions. We anticipate that extending this classical analogue of quantum mechanical spinorbit coupling to twodimensional lattices will lead to exciting new topological phenomena in classical mechanics.
 Publication:

New Journal of Physics
 Pub Date:
 May 2017
 DOI:
 10.1088/13672630/aa6c03
 arXiv:
 arXiv:1609.09651
 Bibcode:
 2017NJPh...19e5001S
 Keywords:

 Condensed Matter  Mesoscale and Nanoscale Physics;
 Condensed Matter  Quantum Gases;
 Physics  Classical Physics
 EPrint:
 New J. Phys. 19 055001 (2017)  Focus issue: Topological Mechanics