Gauge transformation properties of a spinor differential operator
Miftachul Hadi
Abstract
We introduce a spinor differential operator whose expectation value reproduces the Berry connection exactly. We derive its transformation under local $U(1)$ gauge transformations and show that the conventional Berry gauge transformation follows directly through projection onto the normalized spinor. The proposed formulation provides an operator-level formulation of Berry geometry whose projection reproduces the conventional Berry connection and its gauge transformation.