Failure of standard approximations of the exchange coupling in nanostructures

Abstract

We calculate the exchange coupling for a double dot system using a novel, numerically exact yet efficient technique, based on finite-element methods. Specifically, we evaluate the exchange coupling both for a quasi-one and a two-dimensional system, also including an applied magnetic field. Our numerical results provide a stringent test for standard approximation schemes (e.g., Heitler-London, Hund-Mulliken, Hubbard), and they show that the standard methods do not have reliable predictive power for real quantum-dot systems.

arXiv comment7 pages, 4 figures

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Cited by in corpus (29)

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• Implications of Simultaneous Requirements for Low Noise Exchange Gates in Double Quantum Dots
• Quantum theory of the charge stability diagram of semiconductor double quantum dot systems
• Spin-orbit coupling and anisotropic exchange in two-electron double quantum dots
• The Hubbard model as an approximation to the entanglement in nanostructures
• Effect of confinement potential shape on exchange interaction in coupled quantum dots
• Amplified and tunable transverse and longitudinal spin-photon coupling in hybrid circuit-QED
• Configuration interaction calculations of the controlled phase gate in double quantum dot qubits
• Theory of Spin Relaxation in Two-Electron Lateral Coupled Si/SiGe Quantum Dots
• Feasibility of approximating spatial and local entanglement in long-range interacting systems using the extended Hubbard model
• Reliability of the Heitler-London approach for the exchange coupling between electrons in semiconductor nanostructures
• Spin qubits in antidot lattices
• Interplay of exchange and superexchange in triple quantum dots
• Influence of confining potentials on the exchange coupling in double quantum dots
• Extended orbital modeling of spin qubits in double quantum dots
• Size effects in the exchange coupling between two electrons in quantum wire quantum dots
• Path integral study of the role of correlation in exchange coupling of spins in double quantum dots and optical lattices
• Tuning the exchange interaction by electric field in laterally coupled quantum dots
• Low-Dissipation Data Bus via Coherent Quantum Dynamics
• Coupling of bonding and antibonding electron orbitals in double quantum dots by spin-orbit interaction
• Electronic structure and Magneto-transport in MoS${}_2$/Phosphorene van der Waals heterostructure
• Computational Assessment of Silicon Quantum Gate Based on Detuning Mechanism for Quantum Computing
• Spin Hot Spots in Single-Electron GaAs-based Quantum Dots
• Designed defects in 2D antidot lattices for quantum information processing
• Performance Assessment of Resonantly Driven Silicon Two-Qubit Quantum Gate
• Dressed basis sets for the modeling of exchange interactions in double quantum dots
• Comparison of methods for computing the exchange energy in laterally coupled quantum dots