How can I find the documented T1 time of a retired IBM system?

Question

I need to find the published mean T1 time for the 'ibm_oslo' system that I used in an experiment a while back. Unfortunately, that system has now been retired and there's seemingly no way for me to access the system properties window that I can access for all the active systems. I have tried to run on IBM Quantum Labs/Qiskit some code along the lines of:

backend = provider.get_backend('ibm_oslo') system.properties().backend_version system.properties().last_update_date system.properties().qubits

but to no avail. The error is something about this backend cannot be reached... Is there any way to access the system properties of a retired IBM system? Thanks :)

Answer 1

You can look at system properties snapshots of IBM Quantum systems in qiskit-terra either by 1) browsing property snapshot file in https://github.com/Qiskit/qiskit-terra/tree/main/qiskit/providers/fake_provider/backends or 2) retrieving the properties using qiskit.providers.fake_provider module.

1. Browsing property snapshot file.

ibm_oslo property file can be found here: https://github.com/Qiskit/qiskit-terra/blob/main/qiskit/providers/fake_provider/backends/oslo/props_oslo.json

qubit 0 has T1 of 148.84747328441438 us and so on

2. Retrieve using fake backends in qiskit.providers.fake_provider module

from qiskit.providers.fake_provider import FakeOslo

backend = FakeOslo()
backend.qubit_properties(0)

outputs

QubitProperties(t1=0.00014884747328441437, t2=7.369298024352508e-05, frequency=4925043161.619499)

You can pass a list or range to get multiple qubit properties.

backend.qubit_properties(range(7))

outputs

[QubitProperties(t1=0.00014884747328441437, t2=7.369298024352508e-05, frequency=4925043161.619499),
 QubitProperties(t1=0.00013706651413337355, t2=3.7020155523694795e-05, frequency=5046272849.03205),
 QubitProperties(t1=0.00021921703514896735, t2=4.669878652698784e-05, frequency=4961998490.6786995),
 QubitProperties(t1=0.00012128335234199257, t2=4.648766010485143e-05, frequency=5108098767.473062),
 QubitProperties(t1=0.00018813842702629488, t2=0.0001843690321834765, frequency=5011074105.950458),
 QubitProperties(t1=0.00014217817897014813, t2=4.113094933306526e-05, frequency=5173290077.743308),
 QubitProperties(t1=0.00010304578798951729, t2=0.00020846324125703032, frequency=5319311606.468152)]

If you want to get only the list of T1, use python list comprehension:

t1s = [prop.t1 for prop in backend.qubit_properties(range(7))]
print(t1s)

outputs

[0.00014884747328441437, 0.00013706651413337355, 0.00021921703514896735, 0.00012128335234199257, 0.00018813842702629488, 0.00014217817897014813, 0.00010304578798951729]