Intrinsic Metastabilities in the Charge Configuration of a Double Quantum Dot

Abstract

We report a thermally activated metastability in a GaAs double quantum dot exhibiting real-time charge switching in diamond shaped regions of the charge stability diagram. Accidental charge traps and sensor back action are excluded as the origin of the switching. We present an extension of the canonical double dot theory based on an intrinsic, thermal electron exchange process through the reservoirs, giving excellent agreement with the experiment. The electron spin is randomized by the exchange process, thus facilitating fast, gate-controlled spin initialization. At the same time, this process sets an intrinsic upper limit to the spin relaxation time.

4 pages, 5 figures (color)

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• Spectroscopy of Quantum-Dot Orbitals with In-Plane Magnetic Fields
• Phonon-assisted relaxation and decoherence of singlet-triplet qubits in Si/SiGe quantum dots
• Tunneling induced spin dynamics in a quantum dot-lead hybrid system
• Edge State Wave Functions from Momentum-Conserving Tunneling Spectroscopy
• Isotropic and Anisotropic g-factor Corrections in GaAs Quantum Dots
• Quantum measurement induces a many-body transition
• Realizing the interacting resonant level model using a quantum dot detector