Spaces:
Running
Running
| from pytest import raises | |
| import sympy | |
| from sympy.physics.quantum import Dagger, AntiCommutator, qapply | |
| from sympy.physics.quantum.fermion import FermionOp | |
| from sympy.physics.quantum.fermion import FermionFockKet, FermionFockBra | |
| from sympy import Symbol | |
| 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 | |
| def test_power(): | |
| c = FermionOp("c") | |
| assert c**0 == 1 | |
| assert c**1 == c | |
| assert c**2 == 0 | |
| assert c**3 == 0 | |
| assert Dagger(c)**1 == Dagger(c) | |
| assert Dagger(c)**2 == 0 | |
| assert (c**Symbol('a')).func == sympy.core.power.Pow | |
| assert (c**Symbol('a')).args == (c, Symbol('a')) | |
| with raises(ValueError): | |
| c**-1 | |
| with raises(ValueError): | |
| c**3.2 | |
| with raises(TypeError): | |
| c**1j | |