@yuichirominato 2019.02.10更新 97views

## [revised]Quantum teleportation

Introduction

We did quantum teleportation circuit before and now we have much more easier code.

### Quantum teleportation

Quantum states can be photographed by generating quantum entanglement, measuring it, manipulating it, and manipulating the final qubits of the transfer destination with the measurement result.

### The circuit

First prepare the state of q0. Next, q1 and q2 make quantum entanglement. You can achieve quantum entanglement state called EPR pair by applying H gate to q1 and CX on q1 and q2. And it is called bell measurement, make measurements by generating tangle at q0, q1 and applying H gate to q 0. In this case, we will substitute CX / CZ circuit instead of measurement. Originally we will do the measurement instead of CX / CZ and apply X gate, Z gate.

q0 -?-----*-H---*-------
q1 ---H-*-X---*-|-------
q2 -----X-----X-Z-------

Now we have quite simple code on blueqat

from blueqat import Circuit

#Quantum teleportation circuit
a = Circuit().h.cx[1,2].cx[0,1].h.cx[1,2].cz[0,2].m[:]
a.run(shots=100)

Counter({'010': 21, '000': 30, '100': 28, '110': 21})

you can see that the state of q0 is transport to q2

(Circuit().x + a).run(shots=100)

Counter({'001': 25, '111': 23, '101': 24, '011': 28})

if you use H gate for q0 you get 50% of 0 and 50% of 1 on final q2 result.

(Circuit().h + a).run(shots=100)

Counter({'100': 15,
'000': 20,
'111': 16,
'011': 8,
'001': 14,
'101': 8,
'110': 10,
'010': 9})

It’s now much more easier to understand basic circuit using than before.