Bilokon Elvira, Bilokon Valeriia, Lindberg Dusty R, Kaplan Lev, Sotnikov Andrii, Bondar Denys I
Department of Physics and Engineering Physics, Tulane University, New Orleans, LA USA.
Akhiezer Institute for Theoretical Physics, NSC KIPT, Kharkiv, Ukraine.
Commun Phys. 2025;8(1):259. doi: 10.1038/s42005-025-02189-9. Epub 2025 Jun 20.
Understanding quantum tunneling in many-body systems is crucial for advancing quantum technologies and nanoscale device design. Despite extensive studies of quantum tunneling, the role of interactions in determining directional transport through asymmetric barriers in discrete quantum systems remains unclear. Here we show that noninteracting fermions exhibit symmetric tunneling probabilities regardless of barrier orientation, while inter-particle interactions break this symmetry and create pronounced asymmetric tunneling behavior. We explore the dependence of tunneling behavior on the initial spin configurations of two spin-1/2 fermions: spin-triplet states preserve tunneling symmetry, while spin-singlet states show strong asymmetry. We identify regimes where interactions mediate tunneling through under-barrier resonant trapping and enhance tunneling via many-body resonant tunneling - a phenomenon arising solely from inter-particle interactions and being fundamentally different from traditional single-particle resonant tunneling. Our results may be applied to the design of nanoscale devices with tailored transport properties, such as diodes and memristors.
理解多体系统中的量子隧穿对于推动量子技术和纳米级器件设计至关重要。尽管对量子隧穿进行了广泛研究，但相互作用在离散量子系统中通过不对称势垒确定定向输运方面的作用仍不明确。在此我们表明，非相互作用费米子无论势垒取向如何都表现出对称的隧穿概率，而粒子间相互作用会打破这种对称性并产生明显的不对称隧穿行为。我们探究了隧穿行为对两个自旋为1/2的费米子初始自旋构型的依赖性：自旋三重态保持隧穿对称性，而自旋单重态表现出强烈的不对称性。我们确定了相互作用通过势垒下共振俘获介导隧穿并通过多体共振隧穿增强隧穿的区域——这一现象仅由粒子间相互作用产生，与传统的单粒子共振隧穿有根本区别。我们的结果可应用于具有定制输运特性的纳米级器件设计，如二极管和忆阻器。
