Phase space formulation of the Abelian and non-Abelian quantum geometric tensor

Abstract

The geometry of the parameter space is encoded by the quantum geometric tensor, which captures fundamental information about quantum states and contains both the quantum metric tensor and the curvature of the Berry connection. We present a formulation of the Berry connection and the quantum geometric tensor in the framework of the phase space or Wigner function formalism. This formulation is obtained through the direct application of the Weyl correspondence to the geometric structure under consideration. In particular, we show that the quantum metric tensor can be computed using only the Wigner functions, which opens an alternative way to experimentally measure the components of this tensor. We also address the non-Abelian generalization and obtain the phase space formulation of the Wilczek-Zee connection and the non-Abelian quantum geometric tensor. In this case, the non-Abelian quantum metric tensor involves only the non-diagonal Wigner functions. Then, we verify our approach with examples and apply it to a system of $N$ coupled harmonic oscillators, showing that the associated Berry connection vanishes and obtaining the analytic expression for the quantum metric tensor. Our results indicate that the developed approach is well adapted to study the parameter space associated with quantum many-body systems.

22 pages

References in corpus (8)

• Quantum critical scaling of the geometric tensors
• Dynamics of the entanglement between two oscillators in the same environment
• Excited state quantum phase transitions in many-body systems
• Geometry of quantum phase transitions
• Abelian and Non-Abelian Quantum Geometric Tensor
• Critical Property of Geometric Phase in the Dicke Model
• Husimi-Wigner representation of chaotic eigenstates
• The quantum geometric tensor from generating functions

Cited by in corpus (4)

• Quantum geometric tensor and quantum phase transitions in the Lipkin-Meshkov-Glick model
• Extracting non-Abelian quantum metric tensor and its related Chern numbers
• Classical description of the parameter space geometry in the Dicke and Lipkin-Meshkov-Glick models
• Quantum geometric tensor and the topological characterization of the extended Su-Schrieffer-Heeger model