磁场对石墨烯中弱耦合极化子性质的影响

研究了磁场作用下石墨烯中电子与表面光学声子弱耦合情况下的极化子的性质。采用线性组合算符和Pekar变分法分别推导出了石墨烯中弱耦合极化子的基态能量E₀、第一激发态能量E₁和跃迁频率ω随磁场强度B和德拜截止波数k_d之间的变化关系。数值计算结果表明，极化子的基态能量E₀随磁场强度B变化的曲线（k_d一定时）和E₀随k_d的变化曲线（B一定时）均会分裂成对称的两条，并且当B一定时E₀的绝对值随k_d的增加而增加。在k_d一定时，极化子的第一激发态能量E₁和跃迁频率ω均为磁场B的增函数；在B一定时，E₁和ω均随k_d的增加而增大。

Influence of Magnetic Field on The Properties of Weak-coupling Polaron in Graphene

The influence of magnetic field on the polaron properties in the weak coupling of electron and surface optical phonons in monolayer graphene was investigated by using the improved linear combination operator method and the Pekar variational method. The dependences of the energies of the ground state E₀, the first excited state E₁ and the transition frequency ω of weak-coupling polaron on magnetic field B and Debye cut-off wavenumber k_d were derived. Numerical calculations show that the ground state energy E₀ of weak-coupling polaron near the Dirac point is an increasing function of strength of magnetic field B and Debye cut-off wavenumber k_d, the curves of the polaron's ground state energy E₀ of weak-coupling polaron will split into two equal and opposite band; both the first excited state energy E₁ and the transition frequency ω are also an increasing function with strength of magnetic field B and Debye cutoff wavenumbers k_d.