  We study the temperature dependent magnetic susceptibility of a strained
graphene quantum dot by using the determinant quantum Monte Carlo method.
Within the Hubbard model on a honeycomb lattice, our unbiased numerical results
show that a relative small interaction $U$ may lead to a edge ferromagnetic
like behavior in the strained graphene quantum dot, and a possible room
temperature transition is suggested. Around half filling, the ferromagnetic
fluctuations at the zigzag edge is strengthened both markedly by the on-site
Coulomb interaction and the strain, especially in low temperature region. The
resultant strongly enhanced ferromagnetic like behavior may be important for
the development of many applications.
