Minimal Length and Generalized Dirac Equation
  Existence of a minimal observable length which has been indicated by string theory and quantum gravity, leads to a modification of Dirac equation. In this letter we find this modified Dirac equation and solve its eigenvalue problem for a free particle. We will show that due to background spacetime fluctuation, it is impossible to have free particle in Planck scale. 
Kourosh Nozari and Mojdeh Karami