I’m currently working on learning tensor network methods. The Kao group at NTU has built a library to assist with developing tensor network methods called uni10. As I am learning to use uni10 I will helping develop example codes and instructions for first-time users. uni10 is available on gitlab: https://gitlab.com/uni10/uni10
My dissertation research focused on the behavior of a quantum antiferromagnet known as the J-Q model in the presence of an external magnetic field. The J-Q model augments the standard Heisenberg model with a four-spin ‘Q’ term that drives a phase transition to a valence-bond solid (VBS) state. This model has been well-studied in the zero-field limit and I have focused on the effects of an external magnetic field. I primarily rely on stochastic series expansion (SSE) quantum Monte Carlo (QMC).
In 1D the Q term causes the saturation transition to become first order above a critical coupling ratio (Q/J)min: the magnetization jumps to saturation. This is known as metamagnetism and is documented in my first paper. I expand on this in my second paper, demonstrating an exact solution for (Q/J)min =2/9 based on a high-magnetization expansion.