BackwardDisentangler¶

full name: tenpy.algorithms.purification_tebd.BackwardDisentangler
parent module: tenpy.algorithms.purification_tebd
type: class

class tenpy.algorithms.purification_tebd.BackwardDisentangler(parent)[source]¶

Bases: tenpy.algorithms.purification_tebd.Disentangler

Disentangle with backward time evolution.

See [Karrasch2013] for details; only useful during real-time evolution.

For the infinite temperature state, theta = delta_{p0, q0}*delta_{p1, q1}. Thus, an application of U_bond to p0, p1 can be reverted completely by applying U_bond^{dagger} to q0, q1, resulting in the same state. This works also for finite temperatures, since exp(-beta H) and exp(-i H t) commute. Once we apply an operator to measure correlation function, the disentangling breaks down, yet for a local operator only in it’s light-cone.

Arguments and return values are the same as for Disentangler.

Methods

__call__(self, theta)

Find and apply a unitary to disentangle theta.