  A theoretical proposal that Coulomb-coupled quantum dots can be used as
quantum probes to determine the temperature of a sample (i.e., an electronic
reservoir) is proposed. Through the regulation of the positive or negative
voltage bias in the thermometer, we are able to judge whether the temperature
of the sample is higher or lower than that of the reference heat reservoir in
the measure environment and to determine the precise temperature of the sample
by using a particularly simple temperature-voltage bias relationship in the
reversible condition. One outstanding characteristic of the thermometer is that
when the sample is at low temperatures, a small temperature change will lead to
a large voltage bias change. It means that the proposed thermometer has a high
sensitivity when low-temperature samples are measured.
