Optically Accessing Bistable Mode-Locked Precession Frequencies of Electron Spins through Dynamic Nuclear Polarization

The precession frequency of electron spins under conditions of period optical pumping has been observed to remain fixed (i.e., mode-locked) in bands of an externally applied magnetic field [1]. This mode-locking of the electron spin precession frequency is due to the nuclei building up an intrinsic magnetic field, commonly known as the Overhauser field, through dynamic nuclear polarization and electron-nuclear spin interactions. Theoretical analysis and experimental observations have shown that there is an external magnetic field-dependence associated with the Overhauser field leading to an Overhauser field hysteresis [2]. This presentation will outline experimental and computational results demonstrating the effects that an Overhauser field hysteresis has on the electron spin dynamics in periodically pumped gallium arsenide. The presented results demonstrate that the Overhauser field hysteresis induce bistable mode-locked electron spin precession frequencies for a given externally applied magnetic field and provides an intuitive method of optically accessing the bistable mode-locked electron spin precession frequencies [3].

[1] Phys. Rev. B 104, 235204 (2021)

[2] Phys. Rev. B 99, 075201 (2019)

[3] In-Progress