1. *Consider an infinite 1-D ferro-Ising chain a. What is the ground state of this chain? Is it degenerate? b. What is the first excited state of this chain? Is it degenerate? c. Is this system gapped...

1. *Consider an infinite 1-D ferro-Ising chain a. What is the ground state of this chain? Is it degenerate? b. What is the first excited state of this chain? Is it degenerate? c. Is this system gapped or gapless? (Give an example of gapped and gapless systems from the elementary quantum mechanics.)