Quantum metrology based on symmetry-protected adiabatic transformation: imperfection, finite time duration, and dephasing
Quantum metrology based on symmetry-protected adiabatic transformation: imperfection, finite time duration, and dephasing
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DOI：
10.1088/1367-2630/ac5375
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发表时间：
2021-04
影响因子：
3.3
通讯作者：
Takuya Hatomura;Atsuki Yoshinaga;Y. Matsuzaki;Mamiko Tatsuta
中科院分区：
文献类型：
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作者：
Takuya Hatomura;Atsuki Yoshinaga;Y. Matsuzaki;Mamiko Tatsuta
量子计量学的目标是尽可能精确地估计目标参数。在本文中，我们考虑基于对称保护绝热变换的量子计量学。我们引入了一个以横场为探针的铁磁伊辛模型，并考虑了纵场的估计。在没有横向场的情况下，探头的基态由Greenberger-Horne-Zeilinger态给出，因此可以通过宇称测量获得纵场的海森堡极限估计。在我们的方案中，通过对称保护的绝热变换，将编码在宇称上的纵场的全部信息精确地映射到全局磁化，从而可以用全局磁化测量来代替宇称测量。此外，该方案既不需要精确控制单个量子比特，也不需要精确控制相互作用强度。我们讨论了有限横场和非绝热跃迁作为绝热变换的不完备性的影响。通过考虑状态准备、检测和读出的有限持续时间，我们还比较了在没有和存在去相的情况下本方案和经典方案的性能。
The aim of quantum metrology is to estimate target parameters as precisely as possible. In this paper, we consider quantum metrology based on symmetry-protected adiabatic transformation. We introduce a ferromagnetic Ising model with a transverse field as a probe and consider the estimation of a longitudinal field. Without the transverse field, the ground state of the probe is given by the Greenberger–Horne–Zeilinger state, and thus the Heisenberg limit estimation of the longitudinal field can be achieved through parity measurement. In our scheme, full information of the longitudinal field encoded on parity is exactly mapped to global magnetization by symmetry-protected adiabatic transformation, and thus the parity measurement can be replaced with global magnetization measurement. Moreover, this scheme requires neither accurate control of individual qubits nor that of interaction strength. We discuss the effects of the finite transverse field and nonadiabatic transitions as imperfection of adiabatic transformation. By taking into account finite time duration for state preparation, sensing, and readout, we also compare performance of the present scheme with a classical scheme in the absence and presence of dephasing.