Scientists unlock optical control of spin defects in computer chips
Researchers demonstrated precise optical control of chromium impurities embedded in silicon carbide and gallium nitride—two materials already used in power electronics and RF devices. The advance could accelerate development of quantum computers and spintronic devices by providing a practical way to manipulate and read spin states without complex external equipment.
Originaltitel: Resonant optical spectroscopy and coherent control of Cr4+ spin ensembles in SiC and GaN
<p>Spins bound to point defects are increasingly viewed as an important resource for solid-state implementations of quantum information and spintronic technologies. In particular, there is a growing interest in the identification of new classes of defect spin that can be controlled optically. Here, we demonstrate ensemble optical spin polarization and optically detected magnetic resonance (ODMR) of the S = 1 electronic ground state of chromium (Cr4+) impurities in silicon carbide (SiC) and gallium nitride (GaN). Spin polarization is made possible by the narrow optical linewidths of these ensembles (amp;lt;8.5 GHz), which are similar in magnitude to the ground state zero-field spin splitting energies of the ions at liquid helium temperatures. This allows us to optically resolve individual spin sublevels within the ensembles at low magnetic fields using resonant excitation from a cavity-stabilized, narrow-line width laser. Additionally, these near-infrared emitters possess exceptionally weak phonon sidebands, ensuring that amp;gt;73% of the overall optical emission is contained with the defects zero-phonon lines. These characteristics make this semiconductor-based, transition metal impurity system a promising target for further study in the ongoing effort to integrate optically active quantum states within common optoelectronic materials.</p>