Abstract

We explore quantum-thermodynamic effects in a phosphorous (P)-doped graphene monolayer subjected to biaxial tensile strain. Introducing substitutional P atoms in the graphene lattice generates a tunable spin magnetic moment controlled by the strain control parameter ε. This leads to a magnetic quantum phase transition (MQPT) at zero temperature modulated by ε. The system transitions from a magnetic phase, characterized by an out-of-plane sp3 type hybridization of the P-carbon (P-C) bonds, to a non-magnetic phase when these bonds switch to in-plane sp2 hybridization. Employing a Fermi-Dirac statistical model, we calculate key thermodynamic quantities as the electronic entropy Se and electronic specific heat Ce. At finite temperatures, we find the MQPT is reflected in both Se and Ce, which display a distinctive Λ-shaped profile as a function of ε. These thermodynamic quantities sharply increase up to ε = 5% in the magnetic regime, followed by a sudden drop at ε = 5.5%, transitioning to a linear dependence on ε in the nonmagnetic regime. Notably, Se and Ce capture the MQPT behavior for low and moderate temperature ranges, providing insights into the accessible electronic states in P-doped graphene. This controllable magnetic-to-nonmagnetic switch offers potential applications in electronic nanodevices operating at finite temperatures.

Abstract

We explore quantum-thermodynamic effects in a phosphorous (P)-doped graphene monolayer subjected to biaxial tensile strain. Introducing substitutional P atoms in the graphene lattice generates a tunable spin magnetic moment controlled by the strain control parameter ε. This leads to a magnetic quantum phase transition (MQPT) at zero temperature modulated by ε. The system transitions from a magnetic phase, characterized by an out-of-plane sp3 type hybridization of the P-carbon (P-C) bonds, to a non-magnetic phase when these bonds switch to in-plane sp2 hybridization. Employing a Fermi-Dirac statistical model, we calculate key thermodynamic quantities as the electronic entropy Se and electronic specific heat Ce. At finite temperatures, we find the MQPT is reflected in both Se and Ce, which display a distinctive Λ-shaped profile as a function of ε. These thermodynamic quantities sharply increase up to ε = 5% in the magnetic regime, followed by a sudden drop at ε = 5.5%, transitioning to a linear dependence on ε in the nonmagnetic regime. Notably, Se and Ce capture the MQPT behavior for low and moderate temperature ranges, providing insights into the accessible electronic states in P-doped graphene. This controllable magnetic-to-nonmagnetic switch offers potential applications in electronic nanodevices operating at finite temperatures.

Abstract

We explore quantum-thermodynamic effects in a phosphorous (P)-doped graphene monolayer subjected to biaxial tensile strain. Introducing substitutional P atoms in the graphene lattice generates a tunable spin magnetic moment controlled by the strain control parameter ε. This leads to a magnetic quantum phase transition (MQPT) at zero temperature modulated by ε. The system transitions from a magnetic phase, characterized by an out-of-plane sp3 type hybridization of the P-carbon (P-C) bonds, to a non-magnetic phase when these bonds switch to in-plane sp2 hybridization. Employing a Fermi-Dirac statistical model, we calculate key thermodynamic quantities as the electronic entropy Se and electronic specific heat Ce. At finite temperatures, we find the MQPT is reflected in both Se and Ce, which display a distinctive Λ-shaped profile as a function of ε. These thermodynamic quantities sharply increase up to ε = 5% in the magnetic regime, followed by a sudden drop at ε = 5.5%, transitioning to a linear dependence on ε in the nonmagnetic regime. Notably, Se and Ce capture the MQPT behavior for low and moderate temperature ranges, providing insights into the accessible electronic states in P-doped graphene. This controllable magnetic-to-nonmagnetic switch offers potential applications in electronic nanodevices operating at finite temperatures.

Abstract

We explore quantum-thermodynamic effects in a phosphorous (P)-doped graphene monolayer subjected to biaxial tensile strain. Introducing substitutional P atoms in the graphene lattice generates a tunable spin magnetic moment controlled by the strain control parameter ε. This leads to a magnetic quantum phase transition (MQPT) at zero temperature modulated by ε. The system transitions from a magnetic phase, characterized by an out-of-plane sp3 type hybridization of the P-carbon (P-C) bonds, to a non-magnetic phase when these bonds switch to in-plane sp2 hybridization. Employing a Fermi-Dirac statistical model, we calculate key thermodynamic quantities as the electronic entropy Se and electronic specific heat Ce. At finite temperatures, we find the MQPT is reflected in both Se and Ce, which display a distinctive Λ-shaped profile as a function of ε. These thermodynamic quantities sharply increase up to ε = 5% in the magnetic regime, followed by a sudden drop at ε = 5.5%, transitioning to a linear dependence on ε in the nonmagnetic regime. Notably, Se and Ce capture the MQPT behavior for low and moderate temperature ranges, providing insights into the accessible electronic states in P-doped graphene. This controllable magnetic-to-nonmagnetic switch offers potential applications in electronic nanodevices operating at finite temperatures.