Valley-dependent beams controlled by pseudomagnetic field in distorted photonic graphene.

The generation and control of valley pseudospin currents are the core of valleytronics. Here, the photonic analogy for generation and control of valley pseudospin currents using the pseudomagnetic fields induced in strained graphene is investigated in a microwave regime. In photonic graphene with uniaxial distortion, photons in two different valleys experience pseudomagnetic fields with opposite signs, and valley-dependent propagations in bended paths are observed. The external-field-free photonic transportation behavior may be very useful in controlling the flow of light in future valley-polarized devices.