CJT effective potential approach to analyze the nature of phase transition of thermal QED $$_3$$ at finite volume
Yi Hu (School of Physics, Southeast University, Nanjing, 211189, China, National Mobile Communications Research Laboratory, Southeast University, Nanjing, 211189, China, Frontiers Science Center for Mobile Information Communication and Security, Nanjing, Jiangsu, 211111, China, Quantum Information Center of Southeast University, Nanjing, 211189, China); Hong-tao Feng (School of Physics, Southeast University, Nanjing, 211189, China)
Based on the Cornwall–Jackiw–Tomboulis effective potential and the truncated Dyson–Schwinger equations, the nature of phase transition of thermal QED $$_3$$ at finite volume is investigated. We show that, with the rise of temperature, the system undergoes a second-order transition in the chiral limit, and remains exhibiting the second-order with small fermion mass, while it switches to a crossover when the fermion mass exceeds a critical value about $$m_{c}$$ , which diminishes with the increasing volume size and tends to zero in infinite volume.
