2014/04/22 by Tuukka Hiltunen, Ari Harju · 7 citations
Computer Science · Physics and Astronomy · #Charge (physics) #Coupling (piping) #Flux qubit #Materials science #Phase qubit #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum and electron transport phenomena #Quantum decoherence #Quantum mechanics #Qubit #Singlet state #Superconducting quantum computing #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1103/physrevb.90.125303
published in Physical Review B 90(12) (American Physical Society)
arxiv created 2014/04/22 · openalex publication_date 2014/09/05 · arxiv updated 2015/04/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
In the singlet-triplet qubit architecture, the two-qubit interactions required in universal quantum computing can be implemented by capacitative coupling, by exploiting the charge distribution differences of the singlet and triplet states. The efficiency of this scheme is limited by decoherence, that can be mitigated by stronger coupling between the qubits. In this paper, we study the capacitative coupling of singlet-triplet qubits in different geometries of the two-qubit system. The effects of the qubit-qubit distance and the relative orientation of the qubits on the capacitative coupling strength are discussed using an accurate microscopic model and exact diagonalization of it. We find that trapezoidal quantum dot formations allow strong coupling with low charge distribution differences between the singlet and triplet states. The analysis of geometry on the capacitative coupling is also extended to the many-qubit case and the creation of cluster states.