Two electrons in a strongly coupled double quantum dot: from an artificial helium atom to a hydrogen molecule

Abstract

We study the formation of molecular states in a two-electron quantum dot as a function of the barrier potential dividing the dot. The increasing barrier potential drives the two electron system from an artificial helium atom to an artificial hydrogen molecule. To study this strongly coupled regime, we introduce variational wavefunctions which describe accurately two electrons in a single dot, and then study their mixing induced by the barrier. The evolution of the singlet-triplet gap with the barrier potential and with an external magnetic field is analyzed.

10 pages, 11 figures, added references, extended discussion

References in corpus (6)

• The Exchange Gate in Solid State Spin Quantum Computation: The Applicability of the Heisenberg Model
• Spin-blockade spectroscopy of a two-level artificial molecule
• Molecular phases in coupled quantum dots
• Roto-vibrational spectrum and Wigner crystallization in two-electron parabolic quantum dots
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• Single-electron charging and detection in a laterally-coupled quantum dot circuit in the few-electron regime

Cited by in corpus (10)

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• Valley two-qubit system in a MoS${}_2$-monolayer gated double quantum dot
• Exchange interaction and stability diagram of coupled quantum dots in magnetic fields
• Characteristic molecular properties of one-electron double quantum rings under magnetic fields
• Theory of a two-level artificial molecule in laterally coupled quantum Hall droplets
• Size effects in the exchange coupling between two electrons in quantum wire quantum dots
• 3D two-electron double quantum dot: comparison between the behavior of some physical quantities under two different confinement potentials in the presence of a magnetic field
• Tuning the exchange interaction by electric field in laterally coupled quantum dots
• Effect of a laser field in the confinement potential of two electrons in a double quantum dot
• Comparison of methods for computing the exchange energy in laterally coupled quantum dots