triqs.operators.operators
Second-quantization operators and many-body operator algebra.
The Operator class represents an element of the fermionic operator algebra: a linear combination of normally
ordered monomials in creation and annihilation operators, with real or complex coefficients. It supports the full set of
arithmetic operations (+, -, *, / by a scalar) and preserves normal ordering as terms are combined.
Operators are built from the canonical factories:
c()— annihilation operator \(\hat{c}_\alpha\),c_dag()— creation operator \(\hat{c}_\alpha^\dagger\),n()— number operator \(\hat{n}_\alpha = \hat{c}_\alpha^\dagger \hat{c}_\alpha\).
The single-particle state index \(\alpha\) is an arbitrary sequence of integers, strings or floats; new indices are
introduced on the fly as expressions are constructed. The Hermitian conjugate is computed by the free function
dagger(). Higher-level utilities (model Hamiltonians, observables, Coulomb tensors, coefficient extractors) are
provided in triqs.operators.util.
Functions
Create an annihilation operator \(\hat{c}_{\alpha}\). |
|
Create a creation operator \(\hat{c}_{\alpha}^{\dagger}\). |
|
Compute the Hermitian conjugate (dagger) of the many-body operator \(\hat{O}\). |
|
Check if a many-body operator is Hermitian within a given precision. |
|
Create a number operator \(\hat{n}_{\alpha} = \hat{c}_{\alpha}^{\dagger} \hat{c}_{\alpha}\). |
Classes
Second quantization creation/annihilation operator. |
|
Generic many-body operator. |