Confluence of resonant laser excitation and bidirectional quantum-dot nuclear-spin polarization


METADATA ONLY
Loading...

Date

2009-10

Publication Type

Journal Article

ETH Bibliography

yes

Citations

Altmetric
METADATA ONLY

Data

Rights / License

Abstract

Resonant laser scattering along with photon correlation measurements established the atom-like character of quantum dots. Here, we show that for a wide range of experimental parameters it is impossible to isolate elementary quantum-dot excitations from a strong influence of nuclear spins; the absorption lineshapes at magnetic fields exceeding 1 T indicate that the nuclear spins get polarized by an amount that ensures locking of the quantum-dot resonance to the incident laser frequency. In stark contrast to earlier experiments, this nuclear-spin polarization is bidirectional, allowing the combined electron–nuclear-spin system to track the changes in laser frequency dynamically on both sides of the resonance. This unexpected feature stems from a competition between two spin-pumping processes that attempt to polarize nuclear spins in opposite directions. We find that the confluence of laser excitation and nuclear-spin polarization suppresses the fluctuations in resonant absorption. A master-equation analysis suggests narrowing of the nuclear-spin distribution, pointing to applications in quantum information processing.

Publication status

published

Editor

Book title

Volume

5 (10)

Pages / Article No.

758 - 763

Publisher

Nature

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Organisational unit

03833 - Wegscheider, Werner / Wegscheider, Werner check_circle
03636 - Imamoglu, Atac / Imamoglu, Atac check_circle

Notes

Funding

Related publications and datasets