2026/01/26 by J. Craquelin, L. Jarjat, Lucas Jarjat +11
Physics and Astronomy · Materials Science · #Topological Materials and Phenomena #Quantum and electron transport phenomena #Graphene research and applications
paper · pdf · doi:10.1038/s41467-026-68344-0
Controlling the low energy spectrum at the nanoscale with an external physical parameter has become an important resource for quantum devices. The emergence of an energy gap is one such key feature, linked to the mitigation of decoherence needed for quantum information processing. Indeed, the detrimental effects of high-energy uncontrolled excitations can only be cured at some specific tuning points in general. Achieving an energy gap is a natural way to extend decoherence countermeasures over a finite region of parameter space. This would be particularly useful in view of the recent efforts to build superconducting topological chains in a top-down approach. In this work, we demonstrate a large energy gap by spatially modulating the local potential of a suspended carbon nanotube, exploiting an analogy with condensed matter systems. This gap is homogeneous on the nanotube and tunable by about two orders of magnitude, bringing the electronic system from an insulating state to a near-metallic state at low temperatures. Energy gaps can be induced by spatial modulation of the electronic potential. Here, the authors demonstrate a large and robust energy gap in a free-standing carbon nanotube utilizing a 15-gate keyboard that spatially modulates the local potential.