Ferromagnetic proximity effect on the thermodynamic properties of topological crystalline insulator SnTe (001) and related thin films

We provide physical insights into the performance of ferromagnetic proximity effects in both electronic [electronic density of states (DOS)] and thermodynamic features [electronic heat capacity (EHC) and the Pauli spin paramagnetic susceptibility (PSPS)] of topological crystalline insulator SnTe (001) and related thin films. We implement the low-energy Hamiltonian, the Green's function method and the Boltzmann approach. First, we find a gapless phase for SnTe (001) and a gapped one [due to the hybridization between the front and back surfaces] for SnTe (001) thin film. Second, we observe that EHC (PSPS) of gapless SnTe (001) is smaller (greater) than the gapped SnTe (001) thin film. Third, our results show that an exchange field-dependent gap opens in gapless SnTe (001), leading to the increase (decrease) of EHC (PSPS). Fourth, we explain that for exchange fields smaller/greater than the hybridization potential, the inherent gap decreases in SnTe (001) thin film, while it closes if the exchange field becomes equal to the hybridization potential, resulting in the increase (decrease) of EHC (PSPS).