Speaker
Description
We demonstrate that chains of bilayer graphene quantum dots (BLGQDs) can realize topological quantum matter by effectively simulating spin-1 chains that host the Haldane phase. Using an atomistic tight-binding model combined with exact diagonalization, we show that two electrons per quantum dot form a robust spin-1 ground state across interaction regimes. For coupled quantum dots, the low-energy spectrum maps naturally onto a bilinear-biquadratic (BLBQ) spin-1 model, establishing a direct link between microscopic electronic states and effective quantum spin Hamiltonians. Through this mapping, we demonstrate access to the Haldane phase, a topologically ordered phase characterized by a gapped bulk spectrum and fractionalized spin-1/2 edge states. The system parameters are electrically tunable via gate voltages, dielectric environment, and quantum dot geometry, offering unprecedented control over effective spin interactions. Our calculations using density matrix renormalization group methods reveal that chains of 10-20 quantum dots are sufficient to observe clear topological signatures, making this platform experimentally accessible. This work opens new routes for exploring quantum magnetism, topological phases, and electrically controlled quantum information architectures in solid-state systems.
| Keyword-1 | Quantum Dots |
|---|---|
| Keyword-2 | Graphene |
| Keyword-3 | Quantum Materials |