Centre for Quantum Computation and Communication Technology, School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.
School of Physics, University of Melbourne, Parkville, VIC 3010, Australia.
Nat Commun. 2018 Mar 28;9(1):1246. doi: 10.1038/s41467-018-03578-1.
Hyperpolarisation of nuclear spins is important in overcoming sensitivity and resolution limitations of magnetic resonance imaging and nuclear magnetic resonance spectroscopy. Current hyperpolarisation techniques require high magnetic fields, low temperatures, or catalysts. Alternatively, the emergence of room temperature spin qubits has opened new pathways to achieve direct nuclear spin hyperpolarisation. Employing a microwave-free cross-relaxation induced polarisation protocol applied to a nitrogen vacancy qubit, we demonstrate quantum probe hyperpolarisation of external molecular nuclear spins to ~50% under ambient conditions, showing a single qubit increasing the polarisation of ~10 nuclear spins by six orders of magnitude over the thermal background. Results are verified against a detailed theoretical treatment, which also describes how the system can be scaled up to a universal quantum hyperpolarisation platform for macroscopic samples. Our results demonstrate the prospects for this approach to nuclear spin hyperpolarisation for molecular imaging and spectroscopy and its potential to extend beyond into other scientific areas.
核自旋的极化在克服磁共振成像和核磁共振波谱学的灵敏度和分辨率限制方面非常重要。目前的极化技术需要高磁场、低温或催化剂。或者，室温自旋量子位的出现为实现直接核自旋极化开辟了新途径。我们采用一种无需微波的交叉弛豫诱导极化协议，应用于氮空位量子位，在环境条件下实现了外部分子核自旋的量子探针极化度达到50%，表明单个量子位将10 个核自旋的极化度提高了六个数量级，超过了热背景。结果与详细的理论处理进行了验证，该理论处理还描述了如何将系统扩展为用于宏观样品的通用量子极化平台。我们的结果表明，这种核自旋极化方法在分子成像和光谱学方面具有前景，并有可能扩展到其他科学领域。
