def Unitary2Chi(U, B = None):
"""
map unitary process U onto the according chi matrix
option: provide an orthogonal basis B instead of the standard
Pauli basis for the chi matrix
"""
NumberOfQubits = int(np.log2(U.shape[0]))
chidim = 4**NumberOfQubits
a = proctom.getopbase()
A = a
for k in xrange(NumberOfQubits-1):
A = proctom.baseappend(A,a)
lam = np.zeros(chidim, dtype=complex)
for k in xrange(chidim):
lam[k] = np.trace(np.dot(A[k].transpose().conjugate(),U))/2**NumberOfQubits
chi = np.zeros((chidim,chidim), dtype=complex)
for k in xrange(chidim):
for l in xrange(chidim):
chi[k,l]=lam[k]*lam[l].conjugate()
return chi
def Unitary2Chi(U, B=None):
"""
map unitary process U onto the according chi matrix
option: provide an orthogonal basis B instead of the standard
Pauli basis for the chi matrix
"""
NumberOfQubits = int(np.log2(U.shape[0]))
chidim = 4**NumberOfQubits
a = proctom.getopbase()
A = a
for k in xrange(NumberOfQubits - 1):
A = proctom.baseappend(A, a)
lam = np.zeros(chidim, dtype=complex)
for k in xrange(chidim):
lam[k] = np.trace(np.dot(A[k].transpose().conjugate(),
U)) / 2**NumberOfQubits
chi = np.zeros((chidim, chidim), dtype=complex)
for k in xrange(chidim):
for l in xrange(chidim):
chi[k, l] = lam[k] * lam[l].conjugate()
return chi
import time
import scipy.optimize as optimize
import proctom
expm = lnlg.expm
from math import pi
X = np.array([[0,1],[1,0]])
Y = np.array([[0,-1j],[1j,0]])
Z = np.array([[1,0],[0,-1]])
Id = np.array([[1,0],[0,1]])
#Paulis=[Id, X, Y, Z]
Paulis = proctom.getopbase() # added 2010-07-26 by TM: to solve operator definition hickups
def findoptimizedrot(ideal_chi, my_chi, return_chi=False, use_random=True, verbose = True):
"""Finds single qubit operations that maximize the overlap
between an experimental chi matrix and an ideal chi matrix"""
try:
if ideal_chi.shape != my_chi.shape:
raise RuntimeError("Matrices don't have the same dimensions")
except AttributeError:
my_chi = my_chi.chi
nr_of_ions = np.log2(my_chi.shape[0]) / 2
# if nr_of_ions > 1:
# raise NotImplementedError("Can only optimize one qubit by now")
if use_random:
p0 = np.random.random_sample(3*nr_of_ions)
else: