INTRODUCTION TO PATH INTEGRALS
Dante Gatteschi, Roberta Sessoli, Jacques Villain
This chapter introduces the formalism of field theory applied to tunnelling effects, including imaginary time and path integrals. The theory is then specialized by applying the path integral method to spins, and the concept of instanton is introduced. For spins, two paths are possible which lead to interference effects akin to Berry phase.
Oxford University Press eBooks•Mar 2, 2006•1 citation