Nuclear spin temperature reversal via continuous radio-frequency driving

Abstract

Optical spin pumping of color centers in diamond is presently attracting broad interest as a platform for dynamic nuclear polarization at room temperature, but the mechanisms involved in the generation and transport of polarization within the host crystal are still partly understood. Here we investigate the impact of continuous radio-frequency (RF) excitation on the generation of nuclear magnetization produced by optical illumination. In the presence of RF excitation far removed from the nuclear Larmor frequency, we witness a magnetic-field-dependent sign reversal of the measured nuclear spin signal when the drive is sufficiently strong, a counter-intuitive finding that immediately points to non-trivial spin dynamics. With the help of analytical and numerical modeling, we show our observations indicate a modified form of 'solid effect', down-converted from the microwave to the radio-frequency range through the driving of hybrid transitions involving one (or more) nuclei and two (or more) electron spins. Our results open intriguing opportunities for the manipulation of many-electron spin systems by exploiting hyperfine couplings as a means to access otherwise forbidden intra-band transitions.

References in corpus (17)

• A 10-qubit solid-state spin register with quantum memory up to one minute
• Dynamic polarization of single nuclear spins by optical pumping of NV color centers in diamond at room temperature
• Optical polarization of nuclear spins in silicon carbide
• Bulk Nuclear Polarization Enhanced at Room-Temperature by Optical Pumping
• Orientation independent room-temperature optical 13C hyperpolarization in powdered diamond
• High resolution spectroscopy of single NV defects coupled with nearby ${}^{13}$C nuclear spins in diamond
• Local and bulk 13C hyperpolarization in NV-centered diamonds at variable fields and orientations
• Optical polarization of nuclear ensembles in diamond
• Entanglement of dark electron-nuclear spin defects in diamond
• Multi-spin-assisted optical pumping of bulk 13C nuclear spin polarization in diamond
• Microwave-assisted cross-polarization of nuclear spin ensembles from optically-pumped nitrogen-vacancy centers in diamond
• Dynamics of frequency-swept nuclear spin optical pumping in powdered diamond at low magnetic fields
• Two-electron-spin ratchets as a platform for microwave-free dynamic nuclear polarization of arbitrary material targets
• Imaging nuclear spins weakly coupled to a probe paramagnetic center
• All-optical hyperpolarization of electron and nuclear spins in diamond
• Magnetic-field-induced delocalization in hybrid electron-nuclear spin ensembles
• Investigation of room temperature multispin-assisted bulk diamond 13C hyperpolarization at low magnetic fields

Cited by in corpus (2)

• Microwave-free dynamic nuclear polarization via sudden thermal jumps
• Dynamic-nuclear-polarization-weighted spectroscopy of multi-spin electronic-nuclear clusters