Tunneling optoresistance effect and magneto-optoresistance effect in planar heterostructures

We proposed and studied the tunneling optoresistance effect and magneto-optoresistance effect based on planar heterostructures formed by two different types of two-dimensional transition metal dichalcognides (TMDCs). We find that for either intrinsic or modulated planar heterostructures, there exist several ideal line-type resonant peaks in transmission spectra. By tuning the helicity of the off-resonant circularly polarized light irradiated on two modulated regions, the tunneling optoresistance effect can occur, which resembles the tunneling magnetoresistance effect realized by tuning the magnetic exchange field. Compared to cases where only the magnetic exchange field or off-resonant circularly polarized light is introduced, spin- and valley-resolved resonances are suppressed greatly and line-type resonant peaks even disappear, and considerable spin- and valley-resolved high/low resistance states can be achieved through simultaneously switching the direction of the magnetic exchange field and the helicity of the light. We find the magnetic-optical modulation parameters play a great role in the quantum transport process. When the intensity of the magnetic exchange field or the optically induced band gap increases, the tunneling optoresistance effect or the magneto-optoresistance effect can be considerably enhanced. Our results suggest that the tunneling optoresistance effect and magneto-optoresistance effect in TMDC planar heterostructures have a promising potential for applications in magnetic-optical memory and spintronic and valleytronic devices.