Characterizing the rate and coherence of single-electron tunneling between two dangling bonds on the surface of silicon

Abstract

We devise a scheme to characterize tunneling of an excess electron shared by a pair of tunnel-coupled dangling bonds on a silicon surface -- effectively a two-level system. Theoretical estimates show that the tunneling should be highly coherent but too fast to be measured by any conventional techniques. Our approach is instead to measure the time-averaged charge distribution of our dangling-bond pair by a capacitively coupled atomic-force-microscope tip in the presence of both a surface-parallel electrostatic potential bias between the two dangling bonds and a tunable midinfrared laser capable of inducing Rabi oscillations in the system. With a nonresonant laser, the time-averaged charge distribution in the dangling-bond pair is asymmetric as imposed by the bias. However, as the laser becomes resonant with the coherent electron tunneling in the biased pair the theory predicts that the time-averaged charge distribution becomes symmetric. This resonant symmetry effect should not only reveal the tunneling rate, but also the nature and rate of decoherence of single-electron dynamics in our system.

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Cited by in corpus (6)

• Single Electron Dynamics of an Atomic Silicon Quantum Dot on the H-Si(100) 2x1 Surface
• Optimizing surface defects for atomic-scale electronics: Si dangling bonds
• Search for a Metallic Dangling-Bond Wire on $n$-doped H-passivated Semiconductor Surfaces
• Multiple Silicon Dangling-Bond Charge qubits for quantum computing: A Hilbert-Space Analysis of the Hamiltonian
• Quantum Modeling of Scanning Near-Field Optical photons Scattered by an Atomic-Force Microscope Tip for Quantum Metrology
• Characterization and Coherent Control of Spin Qubits with Modulated Electron Beam and Resonator