Optomechanical tension and crumpling of 2D semiconductors

We show that mechanical properties of atomically thin crystals, such as graphene and transition metal dichalcogenides can be efficiently controlled by optical excitation. Illumination by a plane electromagnetic wave with the frequency close to plasmon or exciton resonance affects directly the membrane tension. Depending on the sign of the frequency detuning from the resonance, the membrane is either stretched or crumpled by light. In the latter case, the optomechanical crumpling force competes with the rigidity and the radiation pressure that try to flatten the membrane. When the excitation intensity surpasses the critical value, transition to the crumpled phase occurs.