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arXiv · 2307.02401

Exciton transport in a germanium quantum dot ladder

T. -K. Hsiao·P. Cova Fariña·S. D. Oosterhout·D. Jirovec·X. Zhang·C. J. van Diepen·W. I. L. Lawrie·C. -A. Wang·A. Sammak·G. Scappucci·M. Veldhorst·E. Demler·L. M. K. Vandersypen
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Abstract

Quantum systems with engineered Hamiltonians can be used as simulators of many-body physics problems to provide insights beyond the capabilities of classical computers. Semiconductor gate-defined quantum dot arrays have emerged as a versatile platform for quantum simulation of generalized Fermi-Hubbard physics, one of the richest playgrounds in condensed matter physics. In this work, we employ a germanium 4$\times$2 quantum dot array and show that the naturally occurring long-range Coulomb interaction can lead to exciton formation and transport. We tune the quantum dot ladder into two capacitively-coupled channels and exploit Coulomb drag to probe the binding of electrons and holes. Specifically, we shuttle an electron through one leg of the ladder and observe that a hole is dragged along in the second leg under the right conditions. This corresponds to a transition from single-electron transport in one leg to exciton transport along the ladder. Our work paves the way for the study of excitonic states of matter in quantum dot arrays.

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T. -K. Hsiao, P. Cova Fariña, S. D. Oosterhout, D. Jirovec, X. Zhang, C. J. van Diepen, W. I. L. Lawrie, C. -A. Wang, A. Sammak, G. Scappucci, M. Veldhorst, E. Demler, L. M. K. Vandersypen. 2023-07-05. Exciton transport in a germanium quantum dot ladder. https://doi.org/10.1103/physrevx.14.011048

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