Anyon box in bilayer graphene

forthcoming

Protecting quantum information from environmental interference is essential for advancing quantum technologies. However, reading a quantum state or performing gate operations inevitably involves a coupling to the environment, leading to significant loss of coherence. To address this, the non-local degrees of freedom of topological phases of matter have been proposed for quantum information storage and manipulation. Prototypes of such phases include certain fractional quantum Hall states, found in 2D systems under a strong magnetic field, where pairs of quasiparticles, called non-abelian anyons, share a non-local degree of freedom known as the topological charge. However, detecting the topological charge remains a major experimental challenge due to the narrow energy range over which these states are realized in conventional semiconductor-based platforms. The ANYONBOX project will leverage the recently discovered properties of bilayer graphene, which supports unprecedented robust candidate states for non-abelian anyons, to evidence the topological charge and its potential for quantum information. We will take advantage of the unique electrostatic control achievable with van der Waals heterostructures to isolate anyons confined within electrically tunable potential wells: the anyon boxes. The thermodynamic response when a single anyon is added to the box will be accessed with unmatched resolution through a groundbreaking combination of quantum capacitance and thermal noise measurements. The realization of anyon boxes in bilayer graphene will uncover the elusive topological charge, enabling the measurement of its coherence time, and ultimately, its coherent manipulation through controlled exchanges of the anyon positions, known as non-abelian braiding. ANYONBOX will provide a radically new way of encoding quantum information, opening a new platform for topological quantum information processing with built-in protection against decoherence.