def _evaluate(J1, J2, J3, K):
return ensure_real(
J1 * sum(o.evaluate(context)() for o in self.operators_J1) +
J2 * sum(o.evaluate(context)() for o in self.operators_J2) +
J3 * sum(o.evaluate(context)() for o in self.operators_J3) +
K * sum(o.evaluate(context)() for o in self.operators_K)
)
def _evaluate():
if self.samesite:
return .75 * (context[operators[0]] + context[operators[1]]) # i.e. .75 * rho, scaled by number of sites if summing
else:
return ensure_real(
-.5 * soft_ensure_hermitian(context[operators[4]] + context[operators[5]]) +
+.25 * context[operators[0]] +
+.25 * context[operators[1]] +
-.25 * context[operators[2]] +
-.25 * context[operators[3]]
)
def _evaluate(J, K, Jperp=None):
# of course, Jperp only means what you think it does if the legs
# are long in the x direction
if Jperp is None:
Jperp = J
return ensure_real(
-J * greenx / divx +
-Jperp * greeny / divy +
K * ringexchange / divx / divy
)
def _evaluate(t, J, K, tperp=None, Jperp=None):
# of course, tperp only means what you think it does if the legs
# are long in the x direction
if tperp is None:
tperp = t
if Jperp is None:
Jperp = J
return ensure_real(
-t * greenx / divx +
-tperp * greeny / divy +
J * spinspinx / divx +
Jperp * spinspiny / divy +
2 * K * ringexchange / divx / divy
)
