Strong Electron-Hole Exchange in Coherently Coupled Quantum Dots

Abstract

We have investigated few-body states in vertically stacked quantum dots. Due to small inter-dot tunneling rate, the coupling in our system is in a previously unexplored regime where electron-hole exchange is the dominant spin interaction. By tuning the gate bias, we are able to turn this coupling off and study a complementary regime where total electron spin is a good quantum number. The use of differential transmission allows us to obtain unambiguous signatures of the interplay between electron and hole spin interactions. Small tunnel coupling also enables us to demonstrate all-optical charge sensing, where conditional exciton energy shift in one dot identifies the charging state of the coupled partner.

10 pages, 3 figures

References in corpus (7)

• Single-shot read-out of an individual electron spin in a quantum dot
• Direct Observation of Controlled Coupling in an Individual Quantum Dot Molecule
• Electrically tunable g-factors in quantum dot molecular spin states
• Optically Probing Spin and Charge Interactions in an Tunable Artificial Molecule
• Spin Fine Structure in Optically Excited Quantum Dot Molecules
• Absorption and photoluminescence spectroscopy on a single self-assembled charge-tunable quantum dot
• Coherent optical manipulation of triplet-singlet states in coupled quantum dots

Cited by in corpus (5)

• A nanometer-scale optical electrometer
• Coherent control of indirect excitonic qubits in optically driven quantum dot molecules
• Exchange interaction and tunneling induced transparency in coupled quantum dots
• Single-particle and collective excitations in quantum wires made up of vertically stacked quantum dots: Zero magnetic field
• A coupled quantum dot laser amplifier: Raman transitions between spin singlet and triplet states