  In this study, we focus on the question of stability of NISQ devices. The
parameters that define the device stability profile are motivated by the work
of DiVincenzo where the requirements for physical implementation of quantum
computing are discussed. We develop the metrics and theoretical framework to
quantify the DiVincenzo requirements and study the stability of those key
metrics. The basis of our assessment is histogram similarity (in time and
space). For identical experiments, devices which produce reproducible
histograms in time, and similar histograms in space, are considered more
reliable. To investigate such reliability concerns robustly, we propose a
moment-based distance (MBD) metric. We illustrate our methodology using data
collected from IBM's Yorktown device. Two types of assessments are discussed:
spatial stability and temporal stability.
