PRB147 said:it seems that the Dirac electron in graphene is massless.
No, graphene is not a weird material. It is a highly versatile and remarkable material, known for its strength, flexibility, and conductivity.
The group velocity of graphene depends on various factors such as temperature, doping, and strain. It can range from 10^5 m/s to 10^6 m/s.
Momentum is a physical quantity that describes the movement of an object. In the case of graphene, momentum is closely related to its electronic properties and determines its conductivity and other characteristics.
No, graphene cannot have negative momentum. It follows the laws of classical mechanics, where momentum is always a positive quantity.
No, the group velocity of graphene is not constant. It can vary depending on external factors such as temperature, doping, and strain.