Add backend for MDR Quantum Cloud.
Token management, setup JSON, post JSON, receive JSON and parse as result features are required.

Due to MQC service stopped, MQC backend is obsolated.

The backend which returns sympy's unitary matrix.

Circuit().h[0].run(backend="sympy_unitary")
# => Matrix([
# => [sqrt(2)/2,  sqrt(2)/2],
# => [sqrt(2)/2, -sqrt(2)/2]])

Requrements:

• Use Sympy's Matrix.
• When sympy is not installed, this backend is unavailable however Blueqat and other backends are available.
• At least, following gates shall be implemented: X/Y/Z/U3/RX/RY/RZ/CX/CZ
• Unit test

Optional Requirements:

• Sampling (run(shots=...))
• Pretty output for Jupyter Notebook

For What?

It is convenient to estimate running time on other backend and adjustment optimizer.

What are the concerns?

It may decrease speed.
Vqe.run() may called multiple times.

Implement

• Circuit.statevec() -> np.ndarray
• Circuit.shots() -> Counter[str, int]
• Circuit.oneshot() -> Tuple[np.ndarray, str]

Now:
Circuit().cz(1/2 * math.pi)[0]

Shall be:
Circuit().cz(1/2)[0]

Because almost cases which use rotation, π is required.

Parser for OpenQASM → Blueqat Circuit

In [4]: vqe.non_sampling_sampler(Circuit().x[0].i[2], (0, 1))                                                                                                                                
Out[4]: {(0, 0): 0.0, (0, 1): 1.0, (1, 0): 0.0, (1, 1): 0.0}

• bad
  • {(0, 0): 0.0, (0, 1): 1.0, (1, 0): 0.0, (1, 1): 0.0}
• better
  • {(0, 0): 0.0, (1, 0): 1.0, (0, 1): 0.0, (1, 1): 0.0}
• good
  • {(1, 0): 1.0}

Make optimizer(?) for grid search.

Local instllation isn't be successful. setup.py emerges some errors.

(base) C:\Users\s1430\Downloads\Blueqat-master_test\Blueqat-master>pip install -e .
Obtaining file:///C:/Users/s1430/Downloads/Blueqat-master_test/Blueqat-master
Complete output from command python setup.py egg_info:
Traceback (most recent call last):
File "", line 1, in
File "C:\Users\s1430\Downloads\Blueqat-master_test\Blueqat-master\setup.py", line 4, in
long_description = f.read()
UnicodeDecodeError: 'cp932' codec can't decode byte 0x84 in position 1477: illegal multibyte sequence

----------------------------------------

Command "python setup.py egg_info" failed with error code 1 in C:\Users\s1430\Downloads\Blueqat-master_test\Blueqat-master\

I want to modify blueqat locally for emergent business. I wish this problem will be solved soon.

Now, Circuit class has 3 functionalities.

• Interface to build and run the circuit
• Own the backends and dispatch to them
• Own the gates for the circuit

These features shall be separated.

This is required for numpy and numba backend. However, it's not familiar with caching mechanism.

from blueqat import Circuit

c = Circuit()
c.h[0]
c.cx[0, 1];
c.z[2];

import numpy as np

v1 = c.run_with_numpy()
v2 = c.run_with_numba()
v3 = c.run_with_qgate()

print('numpy')
print(v1)
print('numba')
print(v2)
print('qgate')
print(v3)

Expected: All backends return same result
Actual:

numpy
[0.70710678+0.j 0.        +0.j 0.        +0.j 0.70710678+0.j
 0.        +0.j 0.        +0.j 0.        +0.j 0.        +0.j]
numba
[ 0.70710678+0.j  0.70710678+0.j  0.        +0.j  0.        +0.j
 -0.        +0.j -0.        +0.j -0.        +0.j -0.        +0.j]
qgate
[0.70710678+0.j 0.        +0.j 0.        +0.j 0.70710678+0.j
 0.        +0.j 0.        +0.j 0.        +0.j 0.        +0.j]

How qiskit realize it especially when it's for hardware?

Implement reset gate for numpy, numba backend.

Implement U3, U2, U1, CU3, CU2, CU1 gates.

Now, there's no unit test.

Store tokens to file, and load it.

networkx graph drawing for TN backend.

format string literals f"{foo}" is not working in Python 3.5 or older.

To transfer blueqat circuit, text serializer/deserializer is necessary.

Now, scipy optimizer wrapper set randomized parameter as x0 value.
However, user may know better initial value.

Vqe's Circuit backend shall be selectable.

When will you rerease docker version? It will be helpful for some offices.

Why cu3(0,0,a) doesn't match with cu1(a) ?
Even if I ignore the global phase, these matrices seem different.
I have attached a simple code to check it.

Enviroment: Google Colab.

Get a matrix expression of cu1(a)

circ_test = Circuit(2)
circ_test.cu1(math.pi/4)[0,1]
Matrix = circ_test.to_unitary()
print(Matrix)

It Returns,
Matrix([[exp(-I*pi/16), 0, 0, 0], [0, exp(-I*pi/16), 0, 0], [0, 0, exp(-I*pi/16), 0], [0, 0, 0, exp(3*I*pi/16)]])

Get a matrix expression of cu3(0,0,a)

circ_test = Circuit(2)
circ_test.cu3(0,0,math.pi/4)[0,1]
Matrix = circ_test.to_unitary()
print(Matrix)

It Returns,
Matrix([[1, 0, 0, 0], [0, exp(-I*pi/8), 0, 0], [0, 0, 1, 0], [0, 0, 0, exp(I*pi/8)]])

Even if I ignore the global phase, these matrices seem different.
Is it expected behavior?

On the other hand, non-controlled version of these, namely, u3(0,0,a) and u1(a) , are same.
It is expected behavior.

Get a matrix expression of u1(a)

circ_test = Circuit(1)
circ_test.u1(math.pi/4)[0]
Matrix = circ_test.to_unitary()
print(Matrix)

Matrix([[exp(-I*pi/8), 0], [0, exp(I*pi/8)]])

Get a matrix expression of u3(0,0,a)

circ_test = Circuit(1)
circ_test.u3(0,0,math.pi/4)[0]
Matrix = circ_test.to_unitary()
print(Matrix)

Matrix([[exp(-I*pi/8), 0], [0, exp(I*pi/8)]])

Code:

from blueqat.pauli import I
from blueqat import Circuit
from blueqat.vqe import *

h = 3 * I
runner = Vqe(QaoaAnsatz(h.to_expr()))
runner.run()

Error:

Traceback (most recent call last):
  File "bug_constant_hamiltonian.py", line 6, in <module>
    runner = Vqe(QaoaAnsatz(h.to_expr()))
  File "/home/penguin/blueqat/blueqat/vqe.py", line 64, in __init__
    super().__init__(hamiltonian, step * 2)
  File "/home/penguin/blueqat/blueqat/vqe.py", line 30, in __init__
    self.n_qubits = self.hamiltonian.max_n() + 1
  File "/home/penguin/blueqat/blueqat/pauli.py", line 709, in max_n
    return max(term.max_n() for term in self.terms if term.ops)
ValueError: max() arg is an empty sequence

Likes Qiskit's measure q[i] -> c[j].

The doc directory seems to have api reference, but it isn't included in any toctree. Additionally it should provide an overview page for grabbing overview of the framework at a glance.

Both run in 3.7 and 3.8.

Decomposers are required for ionization trap and superconductivity qubits.

Qgate has this feature, but not implemented in blueqat backend. Implement it.

On new blueqat backend branch, finding n_qubits is too late.

Qiskit specifications changed.

The load_qasm_string() function is deprecated and will be removed in a future release. Instead use QuantumCircuit.from_qasm_str().

Especially, when we implement measurement with creg.
Does m[[i, j]] means "measure i and j" or "measure i into creg j"?

I installed and executed the program of simple quantum circuit. But, keyerror occurs in circuit.py because of 'run_with_numpy'.

Executed program here.

-- coding: utf-8 --

"""
Created on Tue Oct 2 18:54:54 2018

@author: ****
"""

from blueqat import Circuit
import numpy as np
for i in range(100):
c = Circuit().x[3].x[3].x[0].rx(-np.pi/2)[0].ry(np.pi/2)[1]
c = c.cnot[1, 0].rz(np.pi/2)[0].cnot[1, 0].rx(np.pi/2)[0].ry(-np.pi/2)[1].m[:]
c.run()
print(c.last_result()) # => (1, 1)

Result here.
runfile('C:/Users/s1430/blueqatH2vqencitest1.py', wdir='C:/Users/s1430')
Reloaded modules: blueqat, blueqat.circuit, blueqat.gate, blueqat.backends.numpy_backend, blueqat.backends.backendbase, blueqat.backends.qasm_output_backend, blueqat.backends.mqc_backend, blueqat.pauli, blueqat.utils, blueqat.vqe
Traceback (most recent call last):

File "", line 1, in
runfile('C:/Users/s1430/blueqatH2vqencitest1.py', wdir='C:/Users/s1430')

File "C:\Users\s1430\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 705, in runfile
execfile(filename, namespace)

File "C:\Users\s1430\Anaconda3\lib\site-packages\spyder\utils\site\sitecustomize.py", line 102, in execfile
exec(compile(f.read(), filename, 'exec'), namespace)

File "C:/Users/s1430/blueqatH2vqencitest1.py", line 14, in
print(c.last_result()) # => (1, 1)

File "c:\users\s1430\downloads\blueqat-master_new\blueqat-master\blueqat\circuit.py", line 139, in last_result
return self._backends["run_with_numpy"].run_history[-1]

KeyError: 'run_with_numpy'

Implementation of Controlled {RX, RY, RZ, H} gates are required.

Statement

In recent blueqat updates, I guess that default backend is changed from a statevector to a sampler.
How can I use a statevector backend rather than a sampler in the latest blueqat?

Reproduce the problem

In old version of blueqat (probably, 2021),

import math
def print_Zbasis_expression(statevector):
    nqubit = int(math.log2(np.size(statevector)))
    for i in range(2**nqubit):
        print('+({:.2f})*|{number:0{width}b}>'.format(statevector[i],number=i,width=nqubit),end='')

State_out = Circuit(1).h[0].run()
print_Zbasis_expression(State_out)

returns,

+(0.71+0.00j)*|0>+(0.71+0.00j)*|1> 

However, in the latest blueqat (version 2.0.3), the same code returns a different result.

+(0.00)*|0>

I guess that default backend is changed from a statevector to a sampler.

Expected

Circuit(1).h[0].run(backend="statevector")
or
Circuit(1).h[0].run_with_ibmq(backend="statevector")

[0.71+0.00j, 0.71+0.00j]

Thanks.

Add type hinting.

See #80.
Due to this issue, now, numba backend auto test is disabled.