AI 中文总结
本研究通过热力学测量探究GaAs量子点中近藤单态形成的熵抑制，利用电荷传感和麦克斯韦关系得到近藤态特征，其结果与数值重正化群计算及电导测量匹配，验证了近藤态的相关理论。
AI 中文摘要
近藤单态是局域自旋与费米海之间通过纠缠形成的多体态，已通过量子点中的输运特征得到广泛研究。本研究利用温度相关的电荷传感和麦克斯韦关系，对强耦合GaAs量子点添加第一个电子时，与近藤单态形成相关的自旋熵抑制进行热力学测量。将dN/dT与同时测量的占据数N作图，显示出不对称线形，其峰值移至N>1/2处，这是近藤屏蔽的标志，且随温度升高而减弱，数值重正化群（NRG）计算可定性重现该结果，仅存在小但持续的低占据偏移。对同一器件的电导随占据数的独立测量，在混合价交叉区域对这些量进行了检验，且在实验不确定度范围内与NRG结果匹配。
英文摘要
The Kondo singlet---a many-body state formed by entanglement between a localized spin and the Fermi sea---has been studied extensively through its transport signatures in quantum dots. Here we report a thermodynamic measurement of the entropy suppression associated with the formation of the Kondo singlet, using temperature-dependent charge sensing and a Maxwell relation to track the suppression of spin entropy as the first electron is added to a strongly-coupled GaAs quantum dot. Plotting $dN/dT$ against the simultaneously measured occupation $N$ reveals an asymmetric lineshape with its peak shifted to $N>1/2$---a hallmark of Kondo screening---that weakens with increasing temperature and is qualitatively reproduced by numerical renormalization group (NRG) calculations, with a small but persistent offset to lower occupation relative to the theory. An independent measurement of conductance versus occupation on the same device provides a test of these quantities through the mixed-valence crossover and matches NRG within experimental uncertainty.
