Electronic Coherence Control in a Charged Quantum Dot

Abstract

Minimizing decoherence due to coupling of a quantum system to its fluctuating environment is at the forefront of quantum information science and photonics research. Nature sets the ultimate limit, however, given by the strength of the system's coupling to the electromagnetic field. Here, we establish the ability to electronically control this coupling and $\text{enhance}$ the coherence time of a quantum dot excitonic state. Coherence control is demonstrated on the positively charged exciton transition (an electron Coulomb-bound with two holes) in quantum dots embedded in a photonic waveguide by manipulating the electron and hole wavefunctions through an applied lateral electric field. With increasing field up to 15 kV cm${}^{-1}$, the coherence time increases by a factor of two from $\sim 1.4$ ns to $\sim 2.7$ ns. Numerical calculations reveal that longer coherence arises from the separation of charge carriers by up to $\sim 6$ nm, which leads to a $30\%$ weaker transition dipole moment. The ability to electrostatically control the coherence time and transition dipole moment opens new avenues for quantum communication and novel coupling schemes between distant qubits.

12 pages, 3 figures

References in corpus (5)

• Quantum nature of a strongly-coupled single quantum dot-cavity system
• Manipulating exciton fine-structure in quantum dots with a lateral electric field
• Interference of dissimilar photon sources
• Homogeneous Linewidth Narrowing of the Charged Exciton via Nuclear Spin Screening in an InAs/GaAs Quantum Dot Ensemble
• Stimulated Raman spin coherence and spin-flip induced hole burning in charged GaAs quantum dots

Cited by in corpus (9)

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• Quantum teleportation using highly coherent emission from telecom C-band quantum dots
• Inlaid ReS2 Quantum Dots in Monolayer MoS2
• Implementations of more general solid-state (SWAP)${}^{1/m}$ and controlled-(swap)${}^{1/m}$ gates
• Giant Photocurrent Enhancement by Coulomb Interaction in a Single Quantum Dot for Energy Harvesting
• Engineering Quantum Confinement in Semiconducting van der Waals Heterostructure
• Tuning the carrier tunneling in a single quantum dot with a magnetic field in Faraday geometry
• Optical amplitude and phase modulation dynamics at the single-photon level in a quantum dot ridge waveguide
• Charging of a Single InAs QD with Electrically-Injected Holes using a Lateral Electric Field