标题： 量子电动力学中的热退磁与真空退磁 显示英文标题

标题： Thermal Versus Vacuum Magnetization in QED

摘要： 在有限温度和密度下研究了磁化的相对论费米气体和玻色气体。对于费米气体，在高磁场情况下，当热贡献饱和时，来自真空的贡献成为主导。对于带电玻色气体，当气体从抗磁性转变为顺磁性时，（顺磁性的）真空磁化成为主导。我们还发现，对于弱非零外部磁场，标量-QED 有效耦合常数是温度的减小函数。 显示英文摘要

摘要： The magnetized relativistic Fermi and Bose gases are studied at finite temperature and density.In the case of the Fermi gas, the contribution to the magnetization from the vacuum becomes dominant for high magnetic fields, when the thermal contribution saturates. In the case of the charged Bose gas, the (paramagnetic) vacuum--magnetization becomes dominant when the gas changes from a diamagnetic to a paramagnetic behaviour. We furthermore find that the scalar--QED effective coupling constant for a weak non--zero external magnetic field is a decreasing function of the temperature.