Nonlinear dynamics of a two-level system of a single spin driven beyond the rotating-wave approximation
Nonlinear dynamics of a two-level system of a single spin driven beyond the rotating-wave approximation
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DOI：
10.1103/physreva.95.053804
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发表时间：
2016-10
影响因子：
2.9
通讯作者：
K. R. K. Rao-K.-R.-K.-Rao-2107738450;D. Suter
中科院分区：
文献类型：
--
作者：
K. R. K. Rao-K.-R.-K.-Rao-2107738450;D. Suter
由强振荡场驱动的量子系统是许多有趣的物理现象的根源。在这项工作中，我们通过实验研究了强驱动状态下单自旋驱动的两能级系统的动力学，其中旋转波近似无效。这个两能级系统是一个单氮空位中心的子系统，在 $m_{s}$ = $+1$ 和 $-1$ 自旋态之间由于静磁场而产生的能级分裂为 $\approx$ 127 MHz，这大约等于由于静磁场而产生的光谱分裂，在 $m_{s}=\pm1$ 流形中发生的水平反交叉点耦合到金刚石中第一层 $^{13}$C 核自旋。到 $^{13}$C 超精细相互作用。该电子自旋两能级系统在 28.9 G 静磁场中的跃迁频率为 1.7 MHz，并且只能由 RF 场的 $z$ 分量驱动。即使对于中等射频功率，该系统中的电子自旋拉比频率也可以达到数十 MHz。当驱动场的幅度远小于跃迁频率时发生的简单正弦拉比振荡在驱动场强度与能级分裂相当或大于能级分裂时变得复杂。我们观察到系统的振荡速度快于驱动场的振幅，并且系统的响应显示出多个频率。
Quantum systems driven by strong oscillating fields are the source of many interesting physical phenomena. In this work, we experimentally study the dynamics of a two-level system of a single spin driven in the strong-driving regime where the rotating-wave approximation is not valid. This two-level system is a subsystem of a single Nitrogen-Vacancy center coupled to a first-shell $^{13}$C nuclear spin in diamond at a level anti-crossing point that occurs in the $m_{s}=\pm1$ manifold when the energy level splitting between the $m_{s}$ = $+1$ and $-1$ spin states due to the static magnetic field is $\approx$ 127 MHz, which is roughly equal to the spectral splitting due to the $^{13}$C hyperfine interaction. The transition frequency of this electron spin two-level system in a static magnetic field of 28.9 G is 1.7 MHz and it can be driven only by the $z$-component of the RF field. Electron spin Rabi frequencies in this system can reach tens of MHz even for moderate RF powers. The simple sinusoidal Rabi oscillations that occur when the amplitude of the driving field is much smaller than the transition frequency become complex when the driving field strength is comparable or greater than the energy level splitting. We observe that the system oscillates faster than the amplitude of the driving field and the response of the system shows multiple frequencies.