Weldeyesus Henok, Vianez Pedro M T, Sharifi Sedeh Omid, Tan Wooi Kiat, Jin Yiqing, Moreno María, Scheller Christian P, Griffiths Jonathan P, Farrer Ian, Ritchie David A, Zumbühl Dominik M, Ford Christopher J B, Tsyplyatyev Oleksandr
Department of Physics, University of Basel, Basel, Switzerland.
Department of Physics, Cavendish Laboratory, University of Cambridge, Cambridge, UK.
Nat Commun. 2025 Jul 30;16(1):6997. doi: 10.1038/s41467-025-62325-5.
Luttinger liquids occupy a notable place in physics as one of the most understood classes of quantum many-body systems. The experimental mission of measuring its main prediction, power laws in observable quantities, has already produced a body of exponents in different semiconductor and metallic structures. Here, we combine tunneling spectroscopy with density-dependent transport measurements in the same quantum wires over more than two orders of magnitude in temperature to very low electron temperatures down to ∼40 mK. This reveals that, when the second 1D subband becomes populated, the temperature dependence splits into two ranges with different exponents in the power-law dependence of the conductance, both dominated by the finite-size effect of the end-tunneling process. This result demonstrates the importance of measuring the Luttinger parameters as well as the number of modes independently through spectroscopy in addition to the transport exponent in the characterization of Luttinger liquids. This opens a pathway to unambiguous interpretation of the exponents observed in quantum wires.
卢廷格液体在物理学中占据着显著地位，是最容易理解的量子多体系统类别之一。测量其主要预测结果（可观测量中的幂律）的实验任务，已经在不同的半导体和金属结构中得出了一系列指数。在这里，我们将隧穿光谱与密度依赖输运测量相结合，在同一量子线中，温度跨越两个多数量级，直至非常低的电子温度，低至约40 mK。这表明，当第二个一维子带被填充时，温度依赖性在电导的幂律依赖性中分裂为两个具有不同指数的范围，两者均由端隧穿过程的有限尺寸效应主导。这一结果表明，除了输运指数外，通过光谱独立测量卢廷格参数以及模式数量对于卢廷格液体的表征也很重要。这为明确解释量子线中观察到的指数开辟了一条途径。
