Tunable Bistability in Hybrid Bose-Einstein Condensate Optomechanics

Kashif Ammar Yasir, Wu-Ming Liu
2015 Scientific Reports  
Cavity-optomechanics, a rapidly developing area of research, has made a remarkable progress. A stunning manifestation of optomechanical phenomena is in exploiting the mechanical effects of light to couple the optical degree of freedom with mechanical degree of freedom. In this report, we investigate the controlled bistable dynamics of such hybrid optomechanical system composed of cigar-shaped Bose-Einstein condensate (BEC) trapped inside high-finesse optical cavity with one moving-end mirror
more » ... is driven by a single mode optical field. The numerical results provide evidence for controlled optical bistability in optomechanics using transverse optical field which directly interacts with atoms causing the coupling of transverse field with momentum side modes, exited by intra-cavity field. This technique of transverse field coupling is also used to control bistable dynamics of both moving-end mirror and BEC. The report provides an understanding of temporal dynamics of moving-end mirror and BEC with respect to transverse field. Moreover, dependence of effective potential of the system on transverse field has also been discussed. To observe this phenomena in laboratory, we have suggested a certain set of experimental parameters. These findings provide a platform to investigate the tunable behavior of novel phenomenon like electromagnetically induced transparency and entanglement in hybrid systems. In last few years, a lot of investigations have been conducted in the field of cavity-optomechanics. Experimental advances in cavity-optomechanics have made it possible to couple mechanical resonator with optical degree of freedom 1 . Another milestone was achieved by the demonstration of optomechanics when other physical objects, most notably cold atoms or Bose-Einstein condensate, were trapped inside cavity-optomechanics 2 . Both mirror-field interaction and atom-field interaction are needed to develop numerous sensors and devices in quantum metrology, and to study both these phenomena, we rely on hybrid optomechanical systems. In optomechanics, the movable mirror can be cooled down, by the mechanical effects of light, to its quantum mechanical ground state 3-7 , thus providing a platform to study strong coupling effects in hybrid systems [8] [9] [10] [11] . Such extraordinary investigaions in opto-mechanics motivate researchers in developing gravitational wave detectors 12 , measuring displacement with large accuracy 13 and also in developing optomechanical crystals 14 . Recent discussion on bistable behaviour of BEC-optomechanical system 15 , high fidelity state transfer 16,17 , entanglement in optomechanics 18-21 , macroscopic tunneling of an optomechanical membrane 22 and role reversal between matter-wave and quantized light field, are directing and facilitating researchers towards achieving new mile-stones in cavity-optomechanics. Furthermore, the magnificent work on transparency in optomechanics 23-26 , dynamical localization in field of cavity-optomechanics 27,28 and the coupled arrays of micro-cavities 29-32 provide clear understanding for cavity-optomechanics. These notable achievements provide strong foundations to study complex systems and cause curiosity among researchers to explore such hybrid systems and so, a lot of work has been done in this regard [33] [34] [35] [36] [37] .
doi:10.1038/srep10612 pmid:26035206 pmcid:PMC4451843 fatcat:zos26px5uzb4jalgg3fza2xufq