Quantum sensitivity limits of nuclear magnetic resonance experiments searching for new fundamental physics
Quantum sensitivity limits of nuclear magnetic resonance experiments searching for new fundamental physics
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DOI：
10.1088/2058-9565/abfbbc
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发表时间：
2021-07-01
影响因子：
6.7
通讯作者：
Sushkov, Alexander O.
中科院分区：
文献类型：
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作者：
Aybas, Deniz;Bekker, Hendrik;Sushkov, Alexander O.
核磁共振是寻找超轻类轴子暗物质的一种很有前途的实验方法。像宇宙轴子自旋进动实验（CASPEr）这样的实验最终会受到量子力学噪声源的限制，特别是自旋投影噪声。我们讨论如何可能达到这些基本限制。我们考虑一个磁共振实验的电路模型和量化三个噪声源：自旋投影噪声，热噪声和放大器噪声。总噪声谱的计算考虑了核自旋对电路阻抗的影响以及自旋系综对电路的反作用。抑制电路的反作用是特别重要的，以自旋投影噪声限制的搜索类轴子暗物质，以达到量子色动力学轴子的灵敏度。
Nuclear magnetic resonance is a promising experimental approach to search for ultra-light axion-like dark matter. Searches such as the cosmic axion spin-precession experiments (CASPEr) are ultimately limited by quantum-mechanical noise sources, in particular, spin-projection noise. We discuss how such fundamental limits can potentially be reached. We consider a circuit model of a magnetic resonance experiment and quantify three noise sources: spin-projection noise, thermal noise, and amplifier noise. Calculation of the total noise spectrum takes into account the modification of the circuit impedance by the presence of nuclear spins, as well as the circuit back-action on the spin ensemble. Suppression of the circuit back-action is especially important in order for the spin-projection noise limits of searches for axion-like dark matter to reach the quantum chromodynamic axion sensitivity.