Kernel dies when ECR in basis gate set for MPS

[zlatko-minev]

Informations

• Qiskit Aer version: 0.14.1
• Python version: 3.11.8
• Operating system: MacOS

What is the current behavior?

Kernel dies when using ECR basis gate in MPS simulator.

Steps to reproduce the problem

from qiskit import QuantumCircuit, transpile
from qiskit_aer import AerSimulator

qc = QuantumCircuit(2)
qc.h(0)
qc.cx(0, 1)
qc.rz(0.5, 0)
qc.measure_all()

# Works with CX
simulator = AerSimulator(method="matrix_product_state", basis_gates=["cx", "id", "rz", "sx"])
qct = transpile(qc, simulator)
display(qct.draw(output='mpl'))
job = simulator.run(qct)

# Kernel dies with ECR
simulator = AerSimulator(method="matrix_product_state", basis_gates=["ecr", "id", "rz", "sx"])
qct = transpile(qc, simulator)
display(qct.draw(output='mpl'))
job = simulator.run(qct)

Last line causes Kernel to die every time.

What is the expected behavior?

Kernel should not die, simulation should be able to use CX or ECR basis gate, esp. as new devices all use ECR.

Suggested solutions

Unsure

[doichanj]

I'm fixing this issue by 2 steps:

1. Raise error if unsupported gate is passed as basis_gates
2. Add native support for ecr gate in MPS method

[zlatko-minev]

Wonderful, thank you, that sounds good.

We will want to test the ECR to make sure it's implemented faithfully.