Source code for sympy.physics.quantum.piab

"""1D quantum particle in a box."""

from sympy import Symbol, pi, sqrt, sin, Interval, S

from sympy.physics.quantum.operator import HermitianOperator
from sympy.physics.quantum.state import Ket, Bra
from sympy.physics.quantum.constants import hbar
from sympy.functions.special.tensor_functions import KroneckerDelta
from sympy.physics.quantum.hilbert import L2

m = Symbol('m')
L = Symbol('L')


__all__ = [
    'PIABHamiltonian',
    'PIABKet',
    'PIABBra'
]


[docs]class PIABHamiltonian(HermitianOperator): """Particle in a box Hamiltonian operator.""" @classmethod def _eval_hilbert_space(cls, label): return L2(Interval(S.NegativeInfinity,S.Infinity)) def _apply_operator_PIABKet(self, ket, **options): n = ket.label[0] return (n**2*pi**2*hbar**2)/(2*m*L**2)*ket
[docs]class PIABKet(Ket): """Particle in a box eigenket.""" @classmethod def _eval_hilbert_space(cls, args): return L2(Interval(S.NegativeInfinity,S.Infinity)) @classmethod def dual_class(self): return PIABBra def _represent_default_basis(self, **options): return self._represent_XOp(None, **options) def _represent_XOp(self, basis, **options): x = Symbol('x') n = Symbol('n') subs_info = options.get('subs',{}) return sqrt(2/L)*sin(n*pi*x/L).subs(subs_info) def _eval_innerproduct_PIABBra(self, bra): return KroneckerDelta(bra.label[0], self.label[0])
[docs]class PIABBra(Bra): """Particle in a box eigenbra.""" @classmethod def _eval_hilbert_space(cls, label): return L2(Interval(S.NegativeInfinity,S.Infinity)) @classmethod def dual_class(self): return PIABKet