Bloch-Siegert shift in a hybrid quantum register: Quantification and compensation
Bloch-Siegert shift in a hybrid quantum register: Quantification and compensation
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DOI：
10.1103/physreva.98.052354
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发表时间：
2018-06
影响因子：
2.9
通讯作者：
Jingfu Zhang;S. Saha;D. Suter
中科院分区：
文献类型：
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作者：
Jingfu Zhang;S. Saha;D. Suter
量子信息处理依赖于应用于特定量子位的酉变换。在大多数情况下，这些门操作由交变电磁场驱动，这些电磁场与系统哈密顿量本征态之间的特定转变接近谐振。对于单量子位门操作，它们应该在目标量子位上实现操作，而所有其他量子位应保持不变。通常假设，如果控制场的幅度与场和无源量子位的跃迁频率之间的频率差相比较小，则可以实现该目标。然而，在许多情况下，即使是其能级差异与所施加的控制场的频率相距甚远的量子位也会受到非谐振效应的影响，这些效应通常在控制场的幅度上是非线性的。一个典型的例子是称为布洛赫-西格特位移的效应。除非考虑到这些偏移，并且如果可能的话进行补偿，否则它们可能会完全破坏量子寄存器中包含的信息。因此，我们以金刚石中氮空位中心的重要例子定量研究了这种效应，并演示了如何消除它。
Quantum information processing relies on unitary transformations applied to specific qubits. In most cases, these gate operations are driven by alternating electromagnetic fields that are near resonant with specific transitions between eigenstates of the system Hamiltonian. For single-qubit gate operations, they should implement the operation on the target qubit, while all other qubits should be left invariant. It is typically assumed that this goal can be achieved if the amplitude of the control field is small compared to the frequency difference between the field and the transition frequency of the passive qubits. However, in many cases, even qubits whose energy-level differences are very far from the frequency of the applied control field can be affected by nonresonant effects, which are normally nonlinear in the amplitude of the control field. A typical example is the effect known as Bloch-Siegert shift. Unless these shifts are accounted for and, if possible, compensated, they can completely destroy the information contained in the quantum register. Therefore, we study this effect quantitatively in the important example of the nitrogen vacancy center in diamond and demonstrate how it can be eliminated.