Abstract
This study investigates the quantum capacitance ( \({{C}_{Q}}\) ) of a monolayer \({\text{WS}}{{{\text{e}}}_{2}}\) under the influence of an electric field \({{\Delta }_{z}}\) and spin/valley Zeeman fields \({{M}_{z}}\) and \({{M}_{{v}}}\) . The results demonstrate that at low temperatures (10, 30 K), the electric field and Zeeman fields eliminate the abrupt sharp jump in \({{C}_{Q}}\) , leading to a series of smoother, gradual steps. This behavior arises from the increased number of sublevels in the energy structure of \({\text{WS}}{{{\text{e}}}_{2}}\) , induced by external fields. In contrast, at room temperature (approximately 300 K), the thermodynamic effects dominate, resulting in a smooth \({{C}_{Q}}\) curve, regardless of the presence of electric or Zeeman fields. The dip in \({{C}_{Q}}\) within the energy gap region remains a characteristic feature of \({\text{WS}}{{{\text{e}}}_{2}}\) , reflecting its semiconductor nature with a band gap modulated by \({{\Delta }_{z}}\) . These findings highlight the pivotal role of external fields in tuning the quantum capacitance of \({\text{WS}}{{{\text{e}}}_{2}}\) , offering potential insights for the development of advanced nanoelectronic and spintronic devices based on two-dimensional materials.
