Optically induced nuclear spin–spin coupling in semiconductors is expected to serve for gate operations in nuclear-magnetic-resonance (NMR) quantum computations. However, not much is known about its characteristics. In this study, we investigate optically induced couplings in GaAs via double-resonance spin-echo decay experiments under optical pumping. The squared echo decay rate \(\left( {1/T_2} \right)^2\) of ⁷¹Ga measured under various light powers revealed that optically induced couplings increase with increasing light power, and the sign of heteronuclear couplings between Ga–As pairs is opposite to that of dipolar couplings, which cancel each other out. Under higher light power, the optically induced “controllable” coupling is expected to eventually surpass the “uncontrollable” nuclear dipolar coupling, becoming dominant, which is preferable for the gate operation in NMR quantum computation.

半导体中的光诱导核自旋-自旋耦合有望用于核磁共振 (NMR) 量子计算中的门操作。然而，对其特性知之甚少。在这项研究中，我们通过光泵浦下的双共振自旋回波衰减实验研究了 GaAs 中的光诱导耦合。平方回波衰减率\(\left( {1/T_2} \right)^2\)为⁷¹在不同光功率下测量的 Ga 表明，光致耦合随着光功率的增加而增加，并且 Ga-As 对之间的异核耦合的符号与偶极耦合的符号相反，它们相互抵消。在更高的光功率下，预计光诱导的“可控”耦合最终将超过“不可控”的核偶极耦合，成为主导，这对于 NMR 量子计算中的门操作更为可取。