def tensor_rep(G, space):
"build rep of permutation action of G on tensor power of space"
gen = G.items
n = len(gen)
d = len(space)
ring = space.ring
# tensor power of the space
tensor = lambda x, y: x @ y
tspace = reduce(tensor, [space] * n)
# build action on the tensor power
thom = Hom(tspace, tspace)
send_perms = {}
for g in G:
#print(g)
items = []
for idxs in tspace.gen:
jdxs = tuple(idxs[g[i]] for i in range(len(idxs)))
items.append(((idxs, jdxs), ring.one))
#print(idxs, "->", jdxs)
#print()
swap = Map(items, thom)
send_perms[g] = swap
tp = Cat(G, ring)
rep = Rep(send_perms, tspace, tp)
return rep
def build_gates(ring, i4, root2, i8):
qubit = Space(2, ring)
hom = Hom(qubit, qubit)
I = Map.from_array([[1, 0], [0, 1]], hom)
X = Map.from_array([[0, 1], [1, 0]], hom)
Z = Map.from_array([[1, 0], [0, -1]], hom)
H = (1/root2)*(X+Z)
assert H*H == I
S = Map.from_array([[1, 0], [0, i4]], hom)
assert S*S == Z
T = Map.from_array([[1, 0], [0, i8]], hom)
assert S*S == Z
#gen = [X, Z, S] # generates 32 elements
gen = [X, Z, S, H] # generates 192 elements
#gen = [X, Z, S, H, T]
if argv.gap:
print("G := Group(")
ms = []
for g in gen:
m = gapstr(g)
ms.append(m)
print(",\n".join(ms)+");;")
if ring.p <= 41:
G = mulclose(gen)
print("|G| =", len(G))
def __init__(self, send_perms, space, cat):
Element.__init__(self, cat)
assert isinstance(space, Space)
assert isinstance(cat, Cat)
self.send_perms = dict(send_perms)
self.space = space
self.hom = Hom(space, space)
self.G = cat.G
self.ring = cat.ring
def find_span(vs):
rows = []
for v in vs:
v = v.transpose()
row = v.to_array()
assert row.shape[0] == 1
rows.append(row[0])
ring = v.ring
src = v.src
hom = Hom(src, Space(len(vs), ring))
A = Map.from_array(rows, hom)
A = A.transpose()
A = A.image()
return A
def perm_rep(cls, tp):
G = tp.G
ring = tp.ring
one = ring.one
basis = G.items
V = Space(basis, ring)
send_perms = {}
hom = Hom(V, V)
for g in G:
rg = Map([((g[i], i), one) for i in basis], hom)
send_perms[g] = rg
rep = cls(send_perms, V, tp)
return rep
def specht(n, space):
assert n >= 2
d = len(space)
ring = space.ring
items = list(range(n))
gen1 = []
for i in range(n - 1):
perm = dict((item, item) for item in items)
perm[items[i]] = items[i + 1]
perm[items[i + 1]] = items[i]
perm = Perm(perm, items)
gen1.append(perm)
perms = mulclose(gen1)
G = Group(perms, items)
#I = space.ident
# tensor power of the space
tensor = lambda x, y: x @ y
tspace = reduce(tensor, [space] * n)
# build action of symmetric group on the tensor power
thom = Hom(tspace, tspace)
gen2 = []
for g in gen1:
items = []
for idxs in tspace.gen:
jdxs = tuple(idxs[g[i]] for i in range(len(idxs)))
items.append(((idxs, jdxs), ring.one))
#print(idxs, "->", jdxs)
#print()
swap = Map(items, thom)
gen2.append(swap)
action = mulclose_hom(gen1, gen2)
for g in G:
for h in G:
assert action[g *
h] == action[g] * action[h] # check it's a group hom
tp = Cat(G, ring)
rep = Rep(action, tspace, tp)
return rep
def mk_rep(cls, act, tp):
G = tp.G
ring = tp.ring
one = ring.one
gen = act.items
V = Space(gen, ring)
send_perms = {}
hom = Hom(V, V)
for g in G:
ag = act[g]
rg = Map([((ag[i], i), one) for i in gen], hom)
#print(g, "--->")
#print(rg)
send_perms[g] = rg
rep = cls(send_perms, V, tp)
rep.check()
return rep
def main():
#U = numpy.array([[0, 1], [-1, -1]])
V = Space(2, Z)
hom = Hom(V, V)
U = Map.from_array([[0, 1], [-1, -1]], hom)
A = Map.from_array([[1, 0], [0, 1]], hom)
A0 = A
for i in range(2):
print(A)
A = U * A * U.transpose()
A0 = A0 + A
print(A)
print("sum:")
print(A0)
def main():
d = 2
ring = CyclotomicRing(8)
#ring = element.Z
e = ring.x
gamma = e**2
w = gamma**2
assert w == -1
I = numpy.zeros((d, d), dtype=object)
wI = numpy.zeros((d, d), dtype=object)
X = numpy.zeros((d, d), dtype=object)
Z = numpy.zeros((d, d), dtype=object)
Zdag = numpy.zeros((d, d), dtype=object)
S = numpy.zeros((d, d), dtype=object)
Sdag = numpy.zeros((d, d), dtype=object)
T = numpy.zeros((d, d), dtype=object)
Tdag = numpy.zeros((d, d), dtype=object)
for j in range(d):
I[j, j] = 1
wI[j, j] = w
X[j, (j + 1) % d] = 1
Z[j, j] = w**j
Zdag[j, j] = w**(d - j)
val = [1, gamma][j]
ival = [1, -gamma][j]
assert val * ival == 1
S[j, j] = val
Sdag[j, j] = ival
val = [1, e][j]
ival = [1, e**7][j]
assert val * ival == 1
T[j, j] = val
Tdag[j, j] = ival
qu = Space(d, ring)
hom = Hom(qu, qu)
I = Map.from_array(I, hom)
wI = Map.from_array(wI, hom)
Xdag = Map.from_array(X.transpose(), hom)
X = Xs = Map.from_array(X, hom)
Z = Map.from_array(Z, hom)
Zdag = Map.from_array(Zdag, hom)
S = Map.from_array(S, hom)
Sdag = Map.from_array(Sdag, hom)
T = Map.from_array(T, hom)
Tdag = Map.from_array(Tdag, hom)
Y = w * X * Z # ?
assert S * Sdag == I
assert S * S == Z
assert T * T == S
assert Z * Zdag == I
assert X * Xdag == I
if d > 2:
for j in range(1, d + 1):
assert (j == d) == (X**j == I)
assert (j == d) == (Z**j == I)
else:
assert X != I
assert Z != I
assert X * X == I
assert Z * Z == I
assert Z * X == (w**(d - 1)) * X * Z
pauli = mulclose([X, Z, gamma * I])
pauli = set(pauli)
print("pauli:", len(pauli))
assert Zdag in pauli
assert Xdag in pauli
if d < 6:
# slow..
lhs = atpow(X, d)
rhs = atpow(Z, d)
assert lhs * rhs == rhs * lhs
lhs = X @ X
rhs = Z @ Zdag
assert lhs * rhs == rhs * lhs
lhs = X @ (X**(d - 1))
rhs = Z @ Z
assert lhs * rhs == rhs * lhs
if 0:
n = 5
ops = [X, Xdag]
lhs = []
for op in cross([ops] * n):
op = reduce(matmul, op)
lhs.append(op)
ops = [Z, Zdag]
rhs = []
for op in cross([ops] * n):
op = reduce(matmul, op)
rhs.append(op)
for l in lhs:
for r in rhs:
if l * r == r * l:
print("/", end=" ", flush=True)
else:
print(".", end=" ", flush=True)
print()
#print(Z@Z@Z)
#print(Y)
#print(S*X*Sdag)
#print(Y == S*X*Sdag)
if d == 3:
assert (Y == S * X * Sdag)
inverse = {}
for g in pauli:
for h in pauli:
if g * h == I:
inverse[g] = h
inverse[h] = g
def is_cliff(A, Ai):
assert A * Ai == I
for g in pauli:
h = A * g * Ai
if h not in pauli:
return False
return True
print(S)
print(Sdag)
assert is_cliff(S, Sdag)
#print("is_cliff:", (S in pauli), is_cliff(S, Sdag))
def is_third_level(A, Ai):
assert A * Ai == I
for g in pauli:
gi = inverse[g]
h = A * g * Ai * gi
hi = g * A * gi * Ai
if not is_cliff(h, hi):
return False
return True
print("is_pauli(S)", S in pauli)
print("is_cliff(S)", is_cliff(S, Sdag))
#print("is_third_level(S)", is_third_level(S, Tdag))
print("is_pauli(T)", T in pauli)
print("is_cliff(T)", is_cliff(T, Tdag))
print("is_third_level(T)", is_third_level(T, Tdag))
#C2 = mulclose([X, T, H])
print("OK")
def make_dicyclic(n, debug=False):
# Binary dihedral group
# https://people.maths.bris.ac.uk/~matyd/GroupNames/dicyclic.html
p = cyclotomic(PolynomialRing(Z), 4 * n)
ring = PolynomialRing(Z) / p
rzeta = ring.x
zeta = rzeta**2
izeta = zeta**(2 * n - 1) # inverse
for k in range(1, 6 * n):
if zeta**k == 1:
break
assert k == 2 * n
if n == 3:
assert zeta - 1 == zeta**2
i = rzeta**n
assert i != 1
assert i**2 == -1
assert i**3 == -i
assert i**4 == 1
assert zeta**(2 * n) == 1
assert izeta != 1
assert zeta * izeta == 1
def is_real(v): # this is a total hack
assert ring.promote(v) is v
x = exp(2.j * pi / (4 * n))
s = str(v)
v = eval(s, locals())
return abs(v.imag) < EPSILON
for k in range(1, 6 * n):
assert is_real(rzeta**k) == (k % (2 * n) == 0)
assert is_real(zeta + izeta)
# we use the natural 2-dim representation
GL = Linear(2, ring)
e = GL.get([[1, 0], [0, 1]])
r = GL.get([[zeta, 0], [0, izeta]])
s = GL.get([[0, -1], [1, 0]])
Di = mulclose([r, s])
Di = list(Di)
assert len(Di) == 4 * n
eidx = Di.index(e)
ridx = Di.index(r)
sidx = Di.index(s)
G = cayley(Di)
e = G[eidx]
r = G[ridx]
s = G[sidx]
assert r**(2 * n) == e
assert s**2 == r**n
assert r * s * r == s
# complex characters ----------------------------------------------------
# build the transpose of the character table.
cols = []
elems = [] # group elements with order the cols
cgy = [] # element of each cgy class
kidxs = range(2, n)
desc = []
# class: e, size 1
elems.append(e)
cgy.append(e)
desc.append("e")
cols.append([1, 1, 1, 1, 2] + [2 for k in kidxs])
# class: s^2, size 1
cols.append([1, 1, (-1)**n, (-1)**n, -2] + [((-1)**k) * 2 for k in kidxs])
elems.append(s * s)
cgy.append(s * s)
desc.append("s^2")
for idx in range(1, n):
# class: r**idx, size 2
col = [1, 1, (-1)**idx, (-1)**idx, zeta**idx + izeta**idx
] + [zeta**(idx * k) + izeta**(idx * k) for k in kidxs]
cols.append(col)
cols.append(col)
elems.append(r**idx)
cgy.append(r**idx)
desc.append("r^%d" % idx)
elems.append(r**(2 * n - idx))
for idx in range(n):
# class: s, size n
cols.append([1, -1, i**n, -i**n, 0] + [0 for k in kidxs])
elems.append(s * (r**(2 * idx)))
cgy.append(s)
desc.append("s")
for idx in range(n):
# class: s*r, size n
cols.append([1, -1, -i**n, i**n, 0] + [0 for k in kidxs])
elems.append(s * (r**(2 * idx + 1)))
cgy.append(s * r)
desc.append("sr")
#print(i, -i, i**n, -i**n)
assert len(set(elems)) == len(elems) == len(G)
assert set(elems) == set(G)
for col in cols:
assert len(col) == n + 3, len(col)
if debug:
print()
for s in desc:
s = "%10s" % s
print(s, end=" ")
print()
c_chars = []
for k in range(n + 3):
chi = dict((elems[i], cols[i][k]) for i in range(4 * n))
f = CFunc(G, chi)
for g in cgy:
s = "%10s" % (f[g])
print(s, end=" ")
print()
c_chars.append(f)
print()
for f in c_chars:
for g in c_chars:
val = f.dot(g, normalize=False)
#assert (f == g) == (val == 1)
print(val, end=" ")
print()
else:
c_chars = []
for k in range(n + 3):
chi = dict((elems[i], cols[i][k]) for i in range(4 * n))
f = CFunc(G, chi)
c_chars.append(f)
for f in c_chars:
for g in c_chars:
val = f.dot(g)
assert (f == g) == (val == 1)
G.c_chars = c_chars
# complex reps ----------------------------------------------------
c_reps = []
e = G[eidx]
r = G[ridx]
s = G[sidx]
tp = Cat(G, ring)
def mk_rep(gen, reps):
assert reps
f = reps[0]
V = f.hom.src
send_perms = mulclose_hom(gen, reps)
rep = Rep(send_perms, V, tp)
return rep
# 1-dim irreps
V = Space(1, ring)
hom = Hom(V, V)
f_1 = Map.from_array([[1]], hom)
f_n1 = Map.from_array([[-1]], hom)
c_reps.append(mk_rep([r, s], [f_1, f_1])) # Triv
c_reps.append(mk_rep([r, s], [f_1, f_n1])) # 1A
f_r = Map.from_array([[-1]], hom)
f_s = Map.from_array([[i**n]], hom)
c_reps.append(mk_rep([r, s], [f_r, f_s])) # 1B
f_s = Map.from_array([[-i**n]], hom)
c_reps.append(mk_rep([r, s], [f_r, f_s])) # 1C
# 2-dim irreps
V = Space(2, ring)
hom = Hom(V, V)
for k in range(1, n):
rho_r = Map.from_array([[zeta**k, 0], [0, izeta**k]], hom)
rho_s = Map.from_array([[0, 1], [(-1)**k, 0]], hom)
c_reps.append(mk_rep([r, s], [rho_r, rho_s])) # rho_k
for idx, rep in enumerate(c_reps):
rep.check()
char = c_chars[idx]
tr = rep.trace()
tr = CFunc(G, tr)
# print(tr, end=" ")
# val = tr.frobenius_schur()
# if val == -1:
# print("quaternionic")
# elif val == 0:
# print("complex")
# elif val == 1:
# print("real")
# else:
# assert 0, val
for g in G:
lhs, rhs = tr[g], char[g]
assert lhs == rhs, "%d: %s != %s" % (idx, lhs, rhs)
assert len(c_reps) == n + 3
G.c_reps = c_reps
# real characters ----------------------------------------------------
r_chars = []
r_chars.append(c_chars[0]) # Triv
r_chars.append(c_chars[1]) # 1A
if n % 2 == 0:
assert c_chars[2].frobenius_schur() == 1 # real
assert c_chars[3].frobenius_schur() == 1 # real
r_chars.append(c_chars[2]) # 1B
r_chars.append(c_chars[3]) # 1C
else:
assert c_chars[2].frobenius_schur() == 0 # complex
assert c_chars[3].frobenius_schur() == 0 # complex
r_chars.append(c_chars[2] + c_chars[3]) # 1B+1C
for idx, rep in enumerate(c_reps):
if idx < 4:
continue
char = c_chars[idx]
val = char.frobenius_schur()
if val == 1:
r_chars.append(char)
elif val == -1:
r_chars.append(2 * char)
else:
assert 0
G.r_chars = r_chars
return G
def burnside(tp): # make it a method
ring = tp.ring
G = tp.G
Hs = conjugacy_subgroups(G)
names = {}
letters = list(string.ascii_uppercase + string.ascii_lowercase)
letters.remove("O")
letters.remove("o")
letters = letters + [l + "'"
for l in letters] + [l + "''" for l in letters]
assert len(letters) >= len(Hs)
letters = letters[:len(Hs)]
for i, H in enumerate(Hs):
names[H] = "%s_0" % letters[i] # identity coset
acts = {}
for i, H in enumerate(Hs):
cosets = G.left_cosets(H)
assert len(G) == len(cosets) * len(H)
items = [names[H]]
letter = letters[i]
assert H in cosets
idx = 1
for gH in cosets:
if gH == H:
continue
name = "%s_%d" % (letter, idx)
names[gH] = name
items.append(name)
idx += 1
act = G.left_action(cosets)
assert act.src is G
act = act.rename(names, items)
act.name = letter
H.name = act.name
acts[letter] = act
assert len(act.components()) == 1 # transitive
#print act.tgt.perms
print(
"%s subgroup order = %d, number of cosets = %d, conjugates = %d" %
(act.name, len(H), len(cosets), len(H.conjugates)))
#print(list(names.values()))
reps = {}
for act in acts.values():
rep = Rep.mk_rep(act, tp)
reps[act.name] = rep
arg = argv.next() or "B*C"
assert "*" in arg
left, right = arg.split("*")
act0 = acts[left]
act1 = acts[right]
rep0 = reps[left]
rep1 = reps[right]
act2 = act0.pushout(act1)
rep = Rep.mk_rep(act2, tp)
U0 = Space(act0.items, ring)
U1 = Space(act1.items, ring)
UU = U0 @ U1
print(UU)
one = ring.one
hom = Hom(U0, U1)
for act in act2.components():
items = [((y, x), one) for (x, y) in act.items]
f = Map(items, hom)
print(f)
assert tp.is_hom(rep0, rep1, f)
print("kernel:")
g = f.kernel()
print(g)
print()
print("cokernel:")
g = f.cokernel()
print(g)
print()
def main():
d = argv.get("d", 3)
assert d>=2
double = argv.double
if d==2:
ring = CyclotomicRing(4)
#ring = element.Z
gamma = ring.x
w = gamma**2
assert w == -1
double = True
else:
ring = CyclotomicRing(d**2)
gamma = ring.x
w = gamma**d
I = numpy.zeros((d, d), dtype=object)
wI = numpy.zeros((d, d), dtype=object)
X = numpy.zeros((d, d), dtype=object)
Z = numpy.zeros((d, d), dtype=object)
Zdag = numpy.zeros((d, d), dtype=object)
S = numpy.zeros((d, d), dtype=object)
Sdag = numpy.zeros((d, d), dtype=object)
T = numpy.zeros((d, d), dtype=object)
Tdag = numpy.zeros((d, d), dtype=object)
for j in range(d):
I[j, j] = 1
wI[j, j] = w
X[j, (j+1)%d] = 1
Z[j, j] = w**j
Zdag[j, j] = w**(d-j)
if d==2:
val = gamma**(j**2)
ival = gamma**(d**2 - (j**2)%(d**2))
else:
val = w**(j**2)
ival = w**(d - (j**2)%d)
assert val*ival == 1
S[j, j] = val
Sdag[j, j] = ival
if d in [2, 3, 6]:
val = gamma**(j**3)
ival = gamma**(d**2 - (j**3)%(d**2))
else:
val = w**(j**3)
ival = w**(d - (j**3)%d)
assert val*ival == 1
T[j, j] = val
Tdag[j, j] = ival
qu = Space(d, ring)
hom = Hom(qu, qu)
I = Map.from_array(I, hom)
wI = Map.from_array(wI, hom)
Xdag = Map.from_array(X.transpose(), hom)
X = Xs = Map.from_array(X, hom)
Z = Map.from_array(Z, hom)
Zdag = Map.from_array(Zdag, hom)
S = Map.from_array(S, hom)
Sdag = Map.from_array(Sdag, hom)
T = Map.from_array(T, hom)
Tdag = Map.from_array(Tdag, hom)
if d==2:
Y = gamma*X*Z # ?
else:
Y = w*X*Z # ?
assert S*Sdag == I
assert Z*Zdag == I
assert X*Xdag == I
if d>2:
for j in range(1, d+1):
assert (j==d) == (X**j==I)
assert (j==d) == (Z**j==I)
else:
assert X != I
assert Z != I
assert X*X == I
assert Z*Z == I
assert Z*X == (w**(d-1))*X*Z
if double:
pauli = mulclose([X, Z, gamma*I])
names = mulclose_names([X, Z, gamma*I], "X Z i".split())
else:
pauli = mulclose([X, Z])
names = mulclose_names([X, Z, Xdag, Zdag, -I], "X Z Xi Zi -I".split())
pauli = set(pauli)
print("pauli:", len(pauli))
assert Zdag in pauli
assert Xdag in pauli
if d<6:
# slow..
lhs = atpow(X, d)
rhs = atpow(Z, d)
assert lhs * rhs == rhs * lhs
lhs = X@X
rhs = Z@Zdag
assert lhs * rhs == rhs * lhs
lhs = X@(X**(d-1))
rhs = Z@Z
assert lhs * rhs == rhs * lhs
if 0:
n = 5
ops = [X, Xdag]
lhs = []
for op in cross([ops]*n):
op = reduce(matmul, op)
lhs.append(op)
ops = [Z, Zdag]
rhs = []
for op in cross([ops]*n):
op = reduce(matmul, op)
rhs.append(op)
for l in lhs:
for r in rhs:
if l*r == r*l:
print("/", end=" ", flush=True)
else:
print(".", end=" ", flush=True)
print()
print("S =")
print(S)
print("XSX =")
print(X*S*X)
print("XSXS =")
print(X*S*X*S)
#print("Y =")
#print(Y)
#print("S*X*Sdag =")
#print(S*X*Sdag)
assert Y == S*X*Sdag
def get_orbit(g, gi, v):
orbit = [v]
while 1:
u = g*orbit[-1]*gi
if u == orbit[0]:
break
orbit.append(u)
return orbit
print("S orbit:")
for A in [X, Z]:
print('\t', [''.join(names[op]) for op in get_orbit(S, Sdag, A)])
U = X*S
Ui = Sdag * Xdag
assert U*Ui == I
print("XS orbit:")
for A in [X, Z]:
print('\t', [''.join(names[op]) for op in get_orbit(U, Ui, A)])
U = X*X*S
Ui = Sdag * Xdag * Xdag
assert U*Ui == I
print("XXS orbit:")
for A in [X, Z]:
print('\t', [''.join(names[op]) for op in get_orbit(U, Ui, A)])
return
inverse = {}
for g in pauli:
for h in pauli:
if g*h == I:
inverse[g] = h
inverse[h] = g
def is_cliff(A, Ai):
assert A*Ai == I
for g in pauli:
h = A*g*Ai
if h not in pauli:
return False
return True
print("S =")
print(S)
print("S**2 =")
print(S**2)
print("Sdag =")
print(Sdag)
assert is_cliff(S, Sdag)
#print("is_cliff:", (S in pauli), is_cliff(S, Sdag))
def is_third_level(A, Ai):
assert A*Ai == I
for g in pauli:
gi = inverse[g]
h = A*g*Ai*gi
hi = g*A*gi*Ai
if not is_cliff(h, hi):
return False
return True
print("is_pauli(S)", S in pauli)
print("is_cliff(S)", is_cliff(S, Sdag))
#print("is_third_level(S)", is_third_level(S, Tdag))
print("is_pauli(T)", T in pauli)
print("is_cliff(T)", is_cliff(T, Tdag))
print("is_third_level(T)", is_third_level(T, Tdag))
print("OK")
def clifford():
p = argv.get("p", 17)
field = FiniteField(p)
#ring = PolynomialRing(field)
#x = ring.x
for fgen in range(1, p):
items = set()
j = fgen
while j not in items:
items.add(j)
j = (j*fgen)%p
if len(items) == p-1:
break
else:
assert 0
finv = {}
for i in range(1, p):
for j in range(1, p):
if (i*j)%p == 1:
finv[i] = j
finv[j] = i
assert len(finv) == p-1
#print("fgen:", fgen)
items = [field.promote(i) for i in range(p)]
has_imag = [i for i in items if i*i == -1]
#print(p, has_imag)
if not has_imag:
assert 0
i4 = has_imag[0]
assert -i4 == has_imag[1]
has_root2 = [i for i in items if i*i == 2]
if not has_root2:
assert 0
r2 = has_root2[0]
assert -r2 == has_root2[1]
has_i8 = [i for i in items if i*i == i4]
if not has_i8:
assert 0
i8 = has_i8[0]
assert -i8 == has_i8[1]
print("p =", p)
#print(i4, r2, i8)
#print(has_imag, has_root2, has_i8)
for i in items:
if i*i8 == 1:
i8_dag = i
#print(i8_dag)
# try to take a daggar... doesn't really work tho.
assert p==17
dag = {
0:0, 1:1, 2:9, 3:3, 4:13, 5:12, 6:6, 7:7, 8:15,
9:2, 10:10, 11:11, 12:5, 13:4, 14:14, 15:8, 16:16,
}
for (k, v) in list(dag.items()):
dag[k] = field.promote(v)
dag[field.promote(k)] = field.promote(v)
assert dag[i4] == -i4
qubit = Space(2, field)
hom = Hom(qubit, qubit)
def getdag(A):
items = [((j, i), dag[v]) for ((i, j), v) in A.items]
return Map(items, hom)
I = Map.from_array([[1, 0], [0, 1]], hom)
X = Map.from_array([[0, 1], [1, 0]], hom)
Z = Map.from_array([[1, 0], [0, -1]], hom)
H = (1/r2)*(X+Z)
assert H*H == I
S = Map.from_array([[1, 0], [0, i4]], hom)
Sdag = Map.from_array([[1, 0], [0, dag[i4]]], hom)
assert S*S == Z
assert S*Sdag == I
assert getdag(S) == Sdag
T = Map.from_array([[1, 0], [0, i8]], hom)
assert S*S == Z
C1 = mulclose([X, Z])
assert len(C1) == 8
# C1 is Pauli group + phases
#P = fgen*I # phase
P = i4*I
C1 = mulclose([X, Z, P]) # add phases
# assert len(C1) == 64, len(C1)
assert len(C1) == 32, len(C1)
C1_lookup = set(C1)
#gen = [X, Z, S, H]
#C2 = mulclose(gen)
#assert len(C2) == 192
G = []
for a in range(p):
for b in range(p):
for c in range(p):
for d in range(p):
if (a*d - b*c)%p:
G.append(Map.from_array([[a, b], [c, d]], hom))
G_lookup = set(G)
print("|GL(%d, 2)|=%d" % (p, len(G)))
U = []
for g in G:
if g*getdag(g) == I:
U.append(g)
print("|U|=", len(U))
gen = [X, Z, S, H, P]
# Clifford group + phases
C2 = mulclose(gen)
# assert len(C2) == 384, len(C2)
assert len(C2) == 192, len(C2)
C2_lookup = set(C2)
print("|C2| =", len(C2))
print(C2_lookup == set(U))
for g in C2:
assert g in G_lookup
#assert g*getdag(g) == I, str(g) # FAIL
# inv = {I:I}
# for a in G:
# if a in inv:
# continue
# for b in G:
# ab = a*b
# ci = inv.get(ab)
# if ci is None:
# continue
# inv[a] = b*ci
# inv[b] = ci*a
# print(len(inv), end=" ", flush=True)
# print()
inv = {I:I}
remain = set(G)
remain.remove(I)
while remain:
a = iter(remain).__next__()
assert a not in inv
for b in G:
ab = a*b
ci = inv.get(ab)
if ci is None:
continue
if a not in inv:
inv[a] = b*ci
remain.remove(a)
if b not in inv:
inv[b] = ci*a
remain.remove(b)
print(len(inv), end=" ", flush=True)
print()
assert len(inv) == len(G)
if 0:
for g2 in C2:
for g in C1:
assert g2 * g * inv[g2] in C1
C2 = []
for g2 in G:
for g in C1:
if g2*g*inv[g2] not in C1_lookup:
break
else:
C2.append(g2)
assert len(C2) == 384 # same as above
C2_lookup = set(C2)
C3 = []
for g3 in G:
for g in C1:
if g3*g*inv[g3] not in C2_lookup:
break
else:
C3.append(g3)
print("|C3| =", len(C3))
C3_lookup = set(C3)
shuffle(C3)
# count = 0
# for a in C3:
# for b in C3:
# if a*b in C3_lookup:
# count += 1
# print(count)
def src(a):
return set([b for b in C3 if a*b in C3_lookup])
def tgt(a):
return set([b for b in C3 if b*a in C3_lookup])
if 0:
items = iter(C3)
a = items.__next__()
src_a = src(a)
print("|src_a| =", len(src_a))
srcs = []
for b in C3:
src_b = src(b)
if src_b not in srcs:
print("|src_b| = ", len(src_b))
srcs.append(src_b)
if len(srcs)==4: # there is only 4 of these to be found
break
obs = list(srcs)
tgts = []
for b in C3:
tgt_b = tgt(b)
if tgt_b not in obs:
obs.append(tgt_b)
if tgt_b not in tgts:
print("|tgt_b| = ", len(tgt_b))
tgts.append(tgt_b)
if len(tgts)==4: # there is only 4 of these to be found
break
done = False
while not done:
done = True
#print("obs:", len(obs))
obs.sort(key = len, reverse=True)
obs1 = list(obs)
for s in obs:
for t in obs:
st = s.intersection(t)
a = ' '
if st not in obs1:
a = '*'
obs1.append(st)
done = False
#print("%4d"%(len(st)), end=a)
#print()
obs = obs1
obs.sort(key = len, reverse=True)
print("obs:", len(obs), [len(ob) for ob in obs])
for ob in obs:
#print(len(ob), end=" ")
iob = [inv[a] for a in ob if inv[a] in ob]
print((len(ob), len(iob)), end=" ")
print()
def main():
Z = element.Z
ring = element.CyclotomicRing(8)
x = ring.x
r2 = x + x**7
assert r2**2 == 2
qubit = Space(2, ring)
q2 = qubit @ qubit
hom = Hom(qubit, qubit)
I = Map.from_array([[1, 0], [0, 1]], hom)
X = Map.from_array([[0, 1], [1, 0]], hom)
Z = Map.from_array([[1, 0], [0, -1]], hom)
Y = Map.from_array([[0, x**6], [x**2, 0]], hom)
assert Y * Y == I
assert Y == (x**2) * X * Z
II = I @ I
XI = X @ I
IX = I @ X
XX = X @ X
ZI = Z @ I
IZ = I @ Z
assert XI * IX == XX
T = Map.from_array([[1, 0], [0, x]], hom)
Td = Map.from_array([[1, 0], [0, x**7]], hom)
S = T * T
Sd = Td * Td
assert Z == S * S
assert T * Td == I
assert S * Sd == I
assert S * Z == Z * S
assert T * Z == Z * T
assert (Z * X * Z) == -X
assert ((Z @ Z) * (X @ X) * (Z @ Z)) == X @ X
assert ((S @ S) * (X @ X) * (Sd @ Sd)) == atpow((S * X * Sd), 2)
SXSd = S * X * Sd
TXTd = T * X * Td
lhs = r2 * TXTd
i = x**2
assert (lhs == X + i * X * Z)
if 0:
names = mulclose_names([X, Z, x * I], "X Z xI".split())
#print("SXSd:", "*".join(names[SXSd]))
names = mulclose_names([XI, IX, ZI, IZ], "XI IX ZI IZ".split())
g = atpow(SXSd, 2)
#print("*".join(names[g]))
gen = [
X @ I @ I @ I, I @ X @ I @ I, I @ I @ X @ I, I @ I @ I @ X,
Z @ I @ I @ I, I @ Z @ I @ I, I @ I @ Z @ I, I @ I @ I @ Z,
x * (I @ I @ I @ I)
]
names = "XIII IXII IIXI IIIX ZIII IZII IIZI IIIZ wIIII".split()
names = mulclose_names(gen, names)
g = atpow(SXSd, 4)
#print("*".join(names[g]))
g = atpow(TXTd, 4)
assert g not in names
I8, X8, Z8 = atpow(I, 8), atpow(X, 8), atpow(Z, 8)
T8 = atpow(T, 8)
#print(T8.str(hide_zero=True, sep=""))
Td8 = atpow(Td, 8)
G = mulclose([X8, Z8])
P = I8 + X8 + Z8 + X8 * Z8
assert P * P == 4 * P
lhs = P
rhs = T8 * P * Td8
assert (rhs * rhs == 4 * rhs)
#T1 = reduce(matmul, [T, Td]*4)
#T2 = reduce(matmul, [Td, T]*4)
#print(T1*P*T2)
#return
Q = P @ P
RM14 = """
1111111111111111
.1.1.1.1.1.1.1.1
..11..11..11..11
....1111....1111
........11111111
""".strip().split()
RM14.pop(0)
def interp(row, op):
ops = [op if s == "1" else I for s in row]
A = reduce(matmul, ops)
return A
RM14 = [row[1:] for row in RM14] # puncture
n = len(RM14[0])
Sx = [interp(row, X) for row in RM14]
Sz = [interp(row, Z) for row in RM14]
if 0:
print("mulclose...")
G = mulclose(Sx + Sz, maxsize=2**len(Sx + Sz)) # too slow :-(
print(len(G))
P = reduce(add, G)
assert P * P == len(G) * P
Tn = atpow(T, n)
Tdn = atpow(Td, n)
print(P == Tn * P * Tdn)
#print(lhs.str(hide_zero=True, sep=""))
#print()
#print()
#print()
#print(rhs.str(hide_zero=True, sep=""))
gen = [
X @ I @ I @ I @ I @ I @ I @ I, I @ X @ I @ I @ I @ I @ I @ I,
I @ I @ X @ I @ I @ I @ I @ I, I @ I @ I @ X @ I @ I @ I @ I,
I @ I @ I @ I @ X @ I @ I @ I, I @ I @ I @ I @ I @ X @ I @ I,
I @ I @ I @ I @ I @ I @ X @ I, I @ I @ I @ I @ I @ I @ I @ X,
Z @ I @ I @ I @ I @ I @ I @ I, I @ Z @ I @ I @ I @ I @ I @ I,
I @ I @ Z @ I @ I @ I @ I @ I, I @ I @ I @ Z @ I @ I @ I @ I,
I @ I @ I @ I @ Z @ I @ I @ I, I @ I @ I @ I @ I @ Z @ I @ I,
I @ I @ I @ I @ I @ I @ Z @ I, I @ I @ I @ I @ I @ I @ I @ Z,
x * (I @ I @ I @ I @ I @ I @ I @ I)
]
names = """
XIIIIIII IXIIIIII IIXIIIII IIIXIIII IIIIXIII IIIIIXII IIIIIIXI IIIIIIIX
ZIIIIIII IZIIIIII IIZIIIII IIIZIIII IIIIZIII IIIIIZII IIIIIIZI IIIIIIIZ
wIIIIIIII
""".strip().split()
gen.pop(-1)
names.pop(-1)
if 0:
g = atpow(TXTd, 8)
for i in range(8):
print(g == (x**i) * atpow(X * Z, 8))
return
if 0:
names = mulclose_names(gen, names)
g = atpow(TXTd, 8)
for i in range(8):
print(names.get((x**i) * g, "?"))
#for i in [1, 2, 4]:
# print(atpow(TXTd, i))
if 0:
#print(Td*X*T)
X4 = X @ X @ X @ X
T4 = T @ T @ T @ T
Td4 = Td @ Td @ Td @ Td
print(Td4 * X4 * T4)
H = X + Z
E = Map.from_array([[0, 1], [0, 0]], hom) # raising
F = Map.from_array([[0, 0], [1, 0]], hom) # lowering
CNOT = Map.from_array(
[[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 0, 1], [0, 0, 1, 0]], hom @ hom)
SWAP = Map.from_array(
[[1, 0, 0, 0], [0, 0, 1, 0], [0, 1, 0, 0], [0, 0, 0, 1]], hom @ hom)
assert SWAP * SWAP == II
assert CNOT * CNOT == II
G = mulclose([XI, IX, CNOT]) # order 8
G = mulclose([XI, IX, CNOT, SWAP]) # order 24.. must be S_4
G = mulclose([CNOT, SWAP])
# print(len(G))
# for g in G:
# print(g)
A = SWAP @ I
B = I @ SWAP
S_3 = list(mulclose([A, B]))
assert len(S_3) == 6
# for g in G:
# print(g)
# print(g.hom)
hom = A.hom
space = hom.src
N = 2**3
basis = space.get_basis()
orbits = set()
for v in basis:
v1 = space.zero_vector()
for g in S_3:
u = g * v
v1 = v1 + u
orbits.add(v1)
orbits = list(orbits)
# for v in orbits:
# print(v)
HHH = H @ H @ H
v = basis[7]
#print(v)
#print(HHH * v)
print("OK")
def __init__(self, n, space):
assert n >= 2
d = len(space)
ring = space.ring
items = list(range(n))
gen1 = []
for i in range(n - 1):
perm = dict((item, item) for item in items)
perm[items[i]] = items[i + 1]
perm[items[i + 1]] = items[i]
perm = Perm(perm, items)
gen1.append(perm)
perms = mulclose(gen1)
G = Group(perms, items)
#I = space.ident
# tensor power of the space
tensor = lambda x, y: x @ y
tspace = reduce(tensor, [space] * n)
# build action of symmetric group on the tensor power
thom = Hom(tspace, tspace)
gen2 = []
for g in gen1:
items = []
for idxs in tspace.gen:
jdxs = tuple(idxs[g[i]] for i in range(len(idxs)))
items.append(((idxs, jdxs), ring.one))
#print(idxs, "->", jdxs)
#print()
swap = Map(items, thom)
gen2.append(swap)
action = mulclose_hom(gen1, gen2)
for g in G:
for h in G:
assert action[
g * h] == action[g] * action[h] # check it's a group hom
# Build the young symmetrizers
projs = []
parts = []
for part in partitions(n):
if len(part) > d:
continue
parts.append(part)
t = Young(G, part)
rowG = t.get_rowperms()
colG = t.get_colperms()
horiz = None
for g in rowG:
P = action[g]
horiz = P if horiz is None else (horiz + P)
vert = None
for g in colG:
P = action[g]
s = g.sign()
P = s * P
vert = P if vert is None else (vert + P)
A = vert * horiz + horiz * vert
#A = horiz * vert
assert vert * vert == len(colG) * vert
assert horiz * horiz == len(rowG) * horiz
#A = A.transpose()
projs.append(A)
#print(part)
#print(t)
#print(A)
self.projs = projs
self.parts = parts
def main():
#ring = element.Z
ring = element.Q
qubit = Space(2, ring)
q2 = qubit @ qubit
hom = Hom(qubit, qubit)
I = Map.from_array([[1, 0], [0, 1]], hom)
X = Map.from_array([[0, 1], [1, 0]], hom)
Z = Map.from_array([[1, 0], [0, -1]], hom)
H = X + Z
E = Map.from_array([[0, 1], [0, 0]], hom) # raising
F = Map.from_array([[0, 0], [1, 0]], hom) # lowering
II = I @ I
XI = X @ I
IX = I @ X
XX = X @ X
assert XI * IX == XX
CNOT = Map.from_array(
[[1, 0, 0, 0], [0, 1, 0, 0], [0, 0, 0, 1], [0, 0, 1, 0]], hom @ hom)
SWAP = Map.from_array(
[[1, 0, 0, 0], [0, 0, 1, 0], [0, 1, 0, 0], [0, 0, 0, 1]], hom @ hom)
assert SWAP * SWAP == II
assert CNOT * CNOT == II
G = mulclose([XI, IX, CNOT]) # order 8
G = mulclose([XI, IX, CNOT, SWAP]) # order 24.. must be S_4
G = mulclose([CNOT, SWAP])
# print(len(G))
# for g in G:
# print(g)
A = SWAP @ I
B = I @ SWAP
S_3 = list(mulclose([A, B]))
assert len(S_3) == 6
# for g in G:
# print(g)
# print(g.hom)
hom = A.hom
space = hom.src
N = 2**3
basis = space.get_basis()
orbits = set()
for v in basis:
v1 = space.zero_vector()
for g in S_3:
u = g * v
v1 = v1 + u
orbits.add(v1)
orbits = list(orbits)
# for v in orbits:
# print(v)
HHH = H @ H @ H
v = basis[7]
#print(v)
#print(HHH * v)
# ----------------------------------------------------------
specht = Specht(4, qubit)
for i, A in enumerate(specht.projs):
print("part:", specht.parts[i])
print("proj:")
im = A.image()
#im = A
src, tgt = im.hom
for i in src:
for j in tgt:
v = im[j, i]
if v != ring.zero:
print("%s*%s" % (v, j), end=" ")
print()
return
# ----------------------------------------------------------
items = [0, 1, 2, 3]
g1 = Perm({0: 1, 1: 0, 2: 2, 3: 3}, items)
g2 = Perm({0: 0, 1: 2, 2: 1, 3: 3}, items)
g3 = Perm({0: 0, 1: 1, 2: 3, 3: 2}, items)
gen1 = [g1, g2, g3]
s1 = SWAP @ I @ I
s2 = I @ SWAP @ I
s3 = I @ I @ SWAP
gen2 = [s1, s2, s3]
G = mulclose(gen1)
hom = mulclose_hom(gen1, gen2)
for g in G:
for h in G:
assert hom[g * h] == hom[g] * hom[h] # check it's a group hom
projs = []
for part in [(4, ), (3, 1), (2, 2)]:
t = Young(part)
rowG = t.get_rowperms()
colG = t.get_colperms()
horiz = None
for g in rowG:
P = hom[g]
horiz = P if horiz is None else (horiz + P)
vert = None
for g in colG:
P = hom[g]
s = g.sign()
P = s * P
vert = P if vert is None else (vert + P)
A = vert * horiz
#A = horiz * vert
assert vert * vert == len(colG) * vert
assert horiz * horiz == len(rowG) * horiz
#print(t)
#print(A)
projs.append(A)
for A in projs:
for B in projs:
assert A * B == B * A
# print()
# for A in projs:
# for g in G:
# P = hom[g]
# if P*A != A*P:
# print(P*A)
# print(A*P)
# return
for A in projs:
print("proj:")
im = A.image()
#im = A
src, tgt = im.hom
for i in src:
for j in tgt:
v = im[j, i]
if v != ring.zero:
print("%s*%s" % (v, j), end=" ")
print()