  A quantum point contact was used to observe single-electron fluctuations of a
quantum dot in a GaAs heterostructure. The resulting random telegraph signals
(RTS) contain statistical information about the electron spin state if the
tunneling dynamics are spin-dependent. We develop a statistical method to
extract information about spin-dependent dynamics from RTS and use it to
demonstrate that these dynamics can be studied in the thermal energy regime.
The tunneling rates of each spin state are independently measured in a finite
external magnetic field. We confirm previous findings of a decrease in overall
tunneling rates for the spin excited state compared to the ground state as an
external magnetic field is increased.
