37 lines
1.1 KiB
Python
37 lines
1.1 KiB
Python
from sympy.physics.quantum import Dagger, AntiCommutator, qapply
|
|
from sympy.physics.quantum.fermion import FermionOp
|
|
from sympy.physics.quantum.fermion import FermionFockKet, FermionFockBra
|
|
|
|
|
|
def test_fermionoperator():
|
|
c = FermionOp('c')
|
|
d = FermionOp('d')
|
|
|
|
assert isinstance(c, FermionOp)
|
|
assert isinstance(Dagger(c), FermionOp)
|
|
|
|
assert c.is_annihilation
|
|
assert not Dagger(c).is_annihilation
|
|
|
|
assert FermionOp("c") == FermionOp("c", True)
|
|
assert FermionOp("c") != FermionOp("d")
|
|
assert FermionOp("c", True) != FermionOp("c", False)
|
|
|
|
assert AntiCommutator(c, Dagger(c)).doit() == 1
|
|
|
|
assert AntiCommutator(c, Dagger(d)).doit() == c * Dagger(d) + Dagger(d) * c
|
|
|
|
|
|
def test_fermion_states():
|
|
c = FermionOp("c")
|
|
|
|
# Fock states
|
|
assert (FermionFockBra(0) * FermionFockKet(1)).doit() == 0
|
|
assert (FermionFockBra(1) * FermionFockKet(1)).doit() == 1
|
|
|
|
assert qapply(c * FermionFockKet(1)) == FermionFockKet(0)
|
|
assert qapply(c * FermionFockKet(0)) == 0
|
|
|
|
assert qapply(Dagger(c) * FermionFockKet(0)) == FermionFockKet(1)
|
|
assert qapply(Dagger(c) * FermionFockKet(1)) == 0
|