用 150 行 Python 程式碼寫的量子計算模擬器

簡評：讓你更輕鬆地明白，量子計算機如何遵循線性代數計算的。

這是個 GItHub 專案，可以簡單瞭解一下。

qusim.py 是一個多量子位的量子計算機模擬器（玩具？），用 150 行的 python 所編寫。

這段程式碼可以讓你輕鬆瞭解量子計算機如何遵循線性代數來計算的！

from QuSim import QuantumRegister

#############################################
#                 Introduction              #
#############################################
# Here Will Be A Few Example of Different   #
# Quantum States / Algorithms, So You Can   #
# Get A Feel For How The Module Works, and  #
# Some Algorithmic Ideas                    #
#############################################

#############################################
#            Quantum Measurement              #
#############################################
# This experiment will prepare 2 states, of a
# Single qubit, and of 5 qubits, and will just
# Measure them

OneQubit = QuantumRegister(1)  # New Quantum Register of 1 Qubit
print(`One Qubit: ` + OneQubit.measure())  # Should Print `One Qubit: 0`

FiveQubits = QuantumRegister(5)  # New Quantum Register of 5 Qubits
# Should Print `Five Qubits: 00000`
print(`Five Qubits: ` + FiveQubits.measure())

#############################################
#                 Swap 2 Qubits             #
#############################################
# Here, We Will Apply a Pauli-X Gate / NOT Gate
# To the first qubit, and then after the algorithm,
# it will be swapped to the second qubit.

Swap = QuantumRegister(2)  # New Quantum Register of 2 qubits
Swap.applyGate(`X`, 1)  # Apply The NOT Gate. If Measured Now, it should be 10

# Start the swap algorithm
Swap.applyGate(`CNOT`, 1, 2)
Swap.applyGate(`H`, 1)
Swap.applyGate(`H`, 2)
Swap.applyGate(`CNOT`, 1, 2)
Swap.applyGate(`H`, 1)
Swap.applyGate(`H`, 2)
Swap.applyGate(`CNOT`, 1, 2)
# End the swap algorithm

print(`SWAP: |` + Swap.measure() + `>`)  # Measure the State, Should be 01

#############################################
#               Fair Coin Flip              #
#############################################
# Shown in this `Experiment`, is a so called `Fair Coin Flip`,
# Where a state will be prepared, that has an equal chance of
# Flipping to Each Possible State. to do this, the Hadamard
# Gate will be used.

# New Quantum Register of 1 Qubit (As a coin has only 2 states)
FairCoinFlip = QuantumRegister(1)
# If measured at this point, it should be |0>

# Apply the hadamard gate, now theres an even chance of measuring 0 or 1
FairCoinFlip.applyGate(`H`, 1)

# Now, the state will be measured, flipping the state to
# either 0 or 1. If its 0, we will say "Heads", or if its
# 1, we will say "Tails"
FairCoinFlipAnswer = FairCoinFlip.measure()  # Now its flipped, so we can test
if FairCoinFlipAnswer == `0`:
    print(`FairCoinFlip: Heads`)
elif FairCoinFlipAnswer == `1`:
    print(`FairCoinFlip: Tails`)

#############################################
#             CNOT Gate                     #
#############################################
# In this experiment, 4 states will be prepared, {00, 01, 10, 11}
# And then the same CNOT Gate will be run on them,
# To Show The Effects of the CNOT. The Target Qubit will be 2, and the control 1

# New Quantum Register of 2 Qubits, done 4 times.
# If any are measured at this time, the result will be 00
ZeroZero = QuantumRegister(2)
ZeroOne = QuantumRegister(2)
OneZero = QuantumRegister(2)
OneOne = QuantumRegister(2)

# Now prepare Each Into The State Based On Their Name
# ZeroZero Will be left, as thats the first state anyway
ZeroOne.applyGate(`X`, 2)
OneZero.applyGate(`X`, 1)
OneOne.applyGate(`X`, 1)
OneOne.applyGate(`X`, 2)

# Now, a CNOT Will Be Applied To Each.
ZeroZero.applyGate(`CNOT`, 1, 2)
ZeroOne.applyGate(`CNOT`, 1, 2)
OneZero.applyGate(`CNOT`, 1, 2)
OneOne.applyGate(`CNOT`, 1, 2)

# Print the results.
print(`CNOT on 00: |` + ZeroZero.measure() + `>`)
print(`CNOT on 01: |` + ZeroOne.measure() + `>`)
print(`CNOT on 10: |` + OneZero.measure() + `>`)
print(`CNOT on 11: |` + OneOne.measure() + `>`)

主要程式碼來自：corbett/QuantumComputing.

如果你對用 RUST 所寫的高效、高效能的硬體量子計算模擬器有興趣，可以點選 QCGPU 來檢視更多內容。

GITHUB 地址：adamisntdead/QuSimPy