Speaker: Mr. Shubhadeep Nag

Zeros of Grand Canonical Partition Function

Day, Date & Time: Thursday, 13th April, 2017 at 4:00 P.M.

Venue: SSCU Auditorium

In 1952, Chen-Ning Yang and Tsung-Dao Lee published two seminal paper [1,2] in which they studied the equation of state and phase transition of a thermodynamic system by calculating the zeros of the Grand-Canonical partition function, often termed as Lee-Yang zeros. If the zeros have no real solution, then no phase transition would occur. In case there is a phase transition, the zeros will have a real solution in the thermodynamic limit (N tending to infinity). Many valuable information of the thermodynamic system can be obtained by examining the Lee-Yang zeros. It is very difficult to observe directly these complex zeros by experiment as they are not in the physical domain. Wei and Liu mapped the Lee-Yang zeros to the spin coherence zeros of a central spin coupled to many body system [3]. In early 2015, Peng et al. reported direct observation of the Lee-Yang zeros by doing experiment in time domain. They also calculated the free energy of the thermodynamic system and determined its phase transition temperature [4].

[1] C. N. Yang and T. D. Lee, Phys. Rev. 87, 404 (1952).
[2] T. D. Lee and C. N. Yang, Phys. Rev. 87, 410 (1952).
[3] B. B. Wei and R. B. Liu, Phys. Rev. Lett. 109, 185701 (2012).
[4] X. Peng, H. Zhou, B. B. Wei, J. Cui, J. Du and R. B. Liu, Phys. Rev. Lett 114, 010601

All are cordially invited to attend