Year: 2026
Type: preprint
Abstract: Matter-based two-level quantum systems are fundamental building blocks of quantum technologies, underpinning applications in quantum computing, simulation, communication, and sensing. Today, most of these two-level quantum systems, including Rydberg atoms, trapped ions, superconducting circuits, molecules, and quantum dots, involve transition frequencies in microwave or optical domains. However, extending their transition frequency to the THz spectral range could provide numerous benefits, leveraging the unique properties of THz radiation. Here, we show that an hBN-encapsulated graphene double quantum dot realizes a two-level system with a transition frequency in the THz spectral range. Using low-temperature transport spectroscopy in the dark combined with modeling based on nonequilibrium Green's function formalism, we demonstrate the formation of an artificial molecule, featuring bonding and antibonding states separated by an energy of up to 0.6 meV, corresponding to a resonance frequency of 0.145 THz. This approach provides direct access to important parameters of open double quantum dot systems, including tunneling rates, offering a practical alternative to conventional techniques such as photon-assisted tunneling, which are challenging to implement at THz frequencies. The realized 2D-material-based THz two-level system, compatible with direct on-chip integration, could serve as a key building block for future THz quantum technologies. Furthermore, by involving a single-electron transition, coupling these devices to a THz resonator could enable the exploration of ultra-strong light-matter interactions at the fundamental limit of a single transition coupled to a single cavity, beyond the reach of existing THz quantum systems based on collective transitions.
Source: arXiv (Cornell University)
Institutions: Centre National de la Recherche Scientifique, École Normale Supérieure - PSL, Laboratoire de Physique de l'Ecole Normale Supérieure, National Institute for Materials Science, Research Center for Materials Nanoarchitectonics, Université Paris-Saclay, Centre de Nanosciences et de Nanotechnologies, Laboratoire de Physique et d’Étude des Matériaux, ESPCI Paris
Language: English
Subfield: Condensed Matter Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: 青果物価格形成の要因分析, とくに地方の中央卸売市場における価格形成の特徴とその要因について, G2442584775, Terahertz quantum sensing with bilayer graphene quantum dots in resonators, G4162329948, HgTe nanocrystals a new platform for THz optoelectronics, G4806815962, G7080048889, Tera-Hertz generation from femtosecond laser induced micro-plasma, G898758523
OpenAlex ID: W7221523817