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Precise measurements of the dipole moment and polarizability of the neutral exciton and positive trion in a single quantum dot

Lookup NU author(s): Dr Jonathan Mar



This is the final published version of an article that has been published in its final definitive form by American Physical Society, 2017.

For re-use rights please refer to the publisher's terms and conditions.


We perform precise measurements of the permanent dipole moment and polarizability of both the neutral exciton (X0) and positive trion (X+) in a single InAs/GaAs self-assembled quantum dot (QD). This is achieved through one- and two-color high-resolution photocurrent (PC) spectroscopy of X0 and X+, respectively, using ultra-narrow-bandwidth continuous-wave lasers. This technique allows for sub-μeV resolution, which is limited only by the spectral linewidth of the lasers and is more than four orders of magnitude higher than that of previous techniques. We are therefore permitted to obtain precise values for the permanent dipole moment and polarizability of both X0 and X+, by fitting an appropriate theoretical model to the measured transition energies as a function of electric field. As a sequence of protocols for the optical initialization, manipulation, and readout of a QD hole spin qubit embedded in a photodiode device relies on the coherent control of both X0 and X+ as intermediary states, such precise measurements of their dipole moment and polarizability using high-resolution PC spectroscopy are crucial for implementing these quantum computing protocols with high fidelity.

Publication metadata

Author(s): Mar JD, Baumberg JJ, Xu XL, Irvine AC, Williams DA

Publication type: Article

Publication status: Published

Journal: Physical Review B (Rapid Communications)

Year: 2017

Volume: 95

Online publication date: 23/05/2017

Acceptance date: 23/05/2017

Date deposited: 15/06/2020

ISSN (print): 2469-9950

ISSN (electronic): 2469-9969

Publisher: American Physical Society


DOI: 10.1103/PhysRevB.95.201304


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