Interested in learning how to program quantum computers? Then check out our Qiskit textbook Introduction to Quantum Computing with Qiskit.

Introduction

In this tutorial we will explore how to implement the RY gate on IBM’s Quantum Computers with Qiskit.

The RY gate is a rotational gate that does a rotation around the Y-axis by a specified amount which is normally denoted by θ.

The operation of the RY gate can be described using the following matrix:

Using the matrix multiplication we can see how the RY gate operates on the qubits state. For our first example lets initialise the qubits state to |0〉and set θ to be π. This should flip the qubits state from |0〉to |1〉

The associated column vector for |0〉is:

Then multiply the column vector by the RY matrix:

Which has flipped the qubits state from |0〉to |1〉. If we instead initialise the qubit to |1〉and apply the RY gate:

Which has changed the qubits state from |1〉to -|0〉

Implementation

In Qiskit we can implement an RY gate very easily using the following function:

circuit.ry(pi,q[0])

Where pi is the rotation amount and q[0] is the qubit we want to apply the RY gate to.

Go to the code section for the full code example.

How to run the program

Copy and paste the code below in to a python file

Enter your API token in the IBMQ.enable_account('Insert API token here') part
Save and run

Code

from qiskit import QuantumRegister, ClassicalRegister
from qiskit import QuantumCircuit, execute,IBMQ
from qiskit.tools.monitor import job_monitor
import numpy as np

IBMQ.enable_account('ENTER API KEY HERE')
provider = IBMQ.get_provider(hub='ibm-q')

backend = provider.get_backend('ibmq_qasm_simulator')

pi = np.pi

q = QuantumRegister(1,'q')
c = ClassicalRegister(1,'c')

circuit = QuantumCircuit(q,c)

circuit.ry(pi,q[0])
circuit.measure(q,c)

print(circuit)

job = execute(circuit, backend, shots=8192)

job_monitor(job)
counts = job.result().get_counts()

print(counts)

Introduction to the RY gate with code

Introduction

Implementation

How to run the program

Code

Output