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内容記述 |
The silicon vacancy center in Silicon Carbide (SiC) provides an optically addressable qubit at room temperature in its spin-3/2 electronic state. However, optical spin initialization and readout are less efficient compared to those of spin-1 systems, such as nitrogen-vacancy centers in diamond, under non-resonant optical excitation. Spin-dependent fluorescence exhibits contrast only betweenjm ¼ ± 3=2i and jm ¼ ± 1=2i states, and optical pumping does not create a population difference between j þ 1=2i and j 1=2i states. Thus, operating one qubit (e.g., j þ 3=2i;j þ 1=2i states) leaves the population in the remaining state (j 1=2i) unaffected, contributing to background in optical readout. To mitigate this problem, we propose a sensing scheme based on duplex qubit operation in the quartet, using microwave pulses with two resonant frequencies to simultaneouslyoperate j þ 3=2i;j þ 1=2i and j 1=2i;j 3=2i. Experimental results demonstrate that thisapproach doubles signal contrast in optical readout and improves sensitivity in AC magnetometrycompared to simplex operation. |
