Single layer transition metal sulfur compounds as a new two-dimensional semiconductor material, because of its unique characteristics in recent years, the photoelectric characteristics of the concern. In particular, the binding energy of the two dimensional materials can reach hundreds of MeV, which makes the experimental observation room temperature exciton effect possible.
The coupling between the two dimensional materials is weak, so that the different dimension of the material can be formed by stacking the different materials of Van Der Waals, which avoids the limitation of the conventional semiconductor crystal lattice matching. In particular, the formation of a type of electron structure, which is composed of different transition metal sulfur compounds, is formed by the stacking of Van Der Waals.
As an electrically neutral boson, the exciton is very difficult to operate with an electric field and a magnetic field. State Key Laboratory of Chinese Academy of Sciences Institute of semiconductors and semiconductor superlattice often Kai research team using quantum optics approach, by two beams of light coupling layer between the excitons inside the three-level system, the born Oppenheimer approximation can be played birth effect on the motion of the centroid of the exciton additional specifications for term field, equivalent to the exciton is in effective magnetic field in motion. And in two different internal states (Yan Zixuan) on the exciton, the same size, the same symbol, the opposite is equivalent to the opposite of the exciton in the opposite magnetic field. Thus, it is able to separate the different spin states of the exciton space, that is, the Holzer effect of the exciton is realized.
In recent years, the Holzer effect has been extensively studied in the experiment and theory. People will be extended to the photon and cold atomic system, and the work will be extended to the excitation of the neutral solid element system.
Li Jian, Li Li-Kun, Shi Yun-Mei, Zhang, Yang,, Kai,, Dong, and, Wen,, Light-Induced Spin, Exciton Chang in Effect Hall

http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.115.166804 van der Waals, Physical Heterostructures, Review Letters 166804, 115 (2015).