RESUMEN
We propose an ultrahigh-efficiency and broadband all-optical switching scheme based on coherent perfect absorption (CPA) in linear and nonlinear excitation regimes in a cavity quantum electrodynamics (CQED) system. Two separate atomic transitions are excited simultaneously by two signal fields coupled from two ends of an optical cavity under the collective strong coupling condition. Three polariton eigenstates are produced which can be tuned freely by varying system parameters. The output field intensities of multiple channels are zero when the CPA criterion is satisfied. However, destructive quantum interference can be induced by a free-space weak control laser when it is tuned to be resonant to the polariton state. As a consequence, the CQED system acts as a coherent perfect light absorber/transmitter as the control field is turned on/off the polariton resonances. In particular, the proposed scheme may be used to realize broadband multi-throw all-optical switching in the nonlinear excitation regime. The proposed scheme is useful for constructing all-optical routing, all-optical communication networks and various all-optical logic elements.
RESUMEN
We consider a two-dimensional opto-magnomechanical (OMM) system including two optical cavity modes, a magnon mode, a phonon mode, and a collection of two-level atoms. We show how the stationary entanglement between two-level atoms and magnons can be achieved. The presence of two optical cavities leads the atom-magnon entanglement to be achieved in a wide parameter regime. Furthermore, it is shown that one optical cavity can get entangled with magnons, phonons, and the other optical cavity. The entanglement is robust against thermal noise. The work may find applications in building hybrid quantum networks and quantum information processing.
RESUMEN
As propose of organ repair stem cell therapy technology, articular cartilage cannot be repaired by itself has become one of the research hotspots, repair of articular cartilage with mesenchymal stem cells has shown obvious advantages for the treatment. The scholars have made a preliminary study on the role of mesenchymal stem cells from different sources in the repair of knee articular cartilage, and with the combination of transplantation and cartilage tissue engineering, these technologies improved the human cartilage repair effect of bone marrow, adipose, synovium, cord blood derived stem cells, which achieved good clinical curative effect. Due to the different sources, the dominant and recessive factors, each stem cell will have certain advantages and disadvantages. At present, the clinical research is still in the experimental stage, there is no definite conclusion on which kind of stem cell or technology is more suitable for human cartilage repair. This requires the validation of large-scale or combining with new processing technology clinical trials and the long-term clinical effect, it also provides for the basis for further clinical research.