This is a question that I asked on Qiskit ignis section of slack, with a very interesting answer by A Kapila, but I also need to get a short answer in nanoseconds.
I want to evaluate decoherence in function of a waiting time introduced by adding identity gates before the measurement phase (using barriers before and after the series of id gates) For instance for the Essex device, I can obtain the id gate length value using the following code:
device = provider.get_backend('ibmq_essex')
properties = device.properties()
from qiskit.providers.aer.noise.device.parameters import gate_length_values
gate_times_out = gate_length_values(properties)
('id', , 64.0)
Note that this method of creating a delay was used in a published paper about decoherence.
In the methods section the authors give the following description:
« A delay τ is realized via the application of multiple identity operations. Each identity operation has the same duration as a single-qubit rotation gate (80 ns) and is followed by a 10-ns buffer time, which corresponds to a total delay of 90 ns per identity operation. »
For the circuit presented here, the waiting time is 4 * 64 ns = 256 ns plus four times the additional buffer time between gate for the device.
I can find the buffer times in older descriptions of some devices, like the Yorktown (see: https://github.com/Qiskit/ibmq-device-information/blob/master/backends/yorktown/V1/version_log.md). But I cannot find it for the Essex device.What is it? Or where can I find it? Or maybe the waiting time is already included in the gate length values?
Thanks by advance for helping.