Stark tuning and charge state control in individual telecom C-band quantum dots

N N. J. Martin (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) A A. J. Brash (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) A A. Tomlinson (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) E E. M. Sala (EPSRC National Epitaxy Facility, University of Sheffield 2 , Sheffield S1 4DE,) E E. O. Mills (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) C C. L. Phillips (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) R R. Dost (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) L L. Hallacy (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) P P. Millington-Hotze (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) D D. Hallett (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) K K. A. O'Flaherty (EPSRC National Epitaxy Facility, University of Sheffield 2 , Sheffield S1 4DE,) J J. Heffernan (EPSRC National Epitaxy Facility, University of Sheffield 2 , Sheffield S1 4DE,) M M. S. Skolnick (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) A A. M Fox (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,) L L. R. Wilson (School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,)

Abstract

Telecom wavelength quantum dots (QDs) are emerging as a promising solution for generating deterministic single-photons compatible with existing fiber-optic infrastructure. Emission in the low-loss C-band minimizes transmission losses, making them ideal for long-distance quantum communication. In this work, we present a demonstration of both Stark tuning and charge state control of individual InAs/InP QDs operating within the telecom C-band. These QDs are grown by droplet epitaxy and embedded in an InP-based n++-i-n+ heterostructure, fabricated using MOVPE. The gated architecture enables the tuning of emission energy via the quantum-confined Stark effect, with a tuning range exceeding 2.4 nm. It also allows for control over the QD charge occupancy, enabling access to multiple discrete excitonic states. Electrical tuning of the fine-structure splitting is further demonstrated, opening a route to entangled-photon-pair generation at telecom wavelengths. The single-photon character is confirmed via second-order correlation measurements. These advances enable QDs to be tuned into resonance with other systems, such as cavity modes and emitters, marking a critical step toward scalable, fiber-compatible quantum photonic devices.

Article Details

Volume / Issue Vol. 127, Issue 19
Published November 10, 2025
ISSN 0003-6951
Publisher American Institute of Physics

Journal Info

Applied Physics Letters

American Institute of Physics

ISSN: 0003-6951 Physical Sciences

Authors (15)

N

N. J. Martin

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

A

A. J. Brash

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

A

A. Tomlinson

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

E

E. M. Sala

EPSRC National Epitaxy Facility, University of Sheffield 2 , Sheffield S1 4DE,

E

E. O. Mills

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

C

C. L. Phillips

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

R

R. Dost

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

L

L. Hallacy

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

P

P. Millington-Hotze

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

D

D. Hallett

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

K

K. A. O'Flaherty

EPSRC National Epitaxy Facility, University of Sheffield 2 , Sheffield S1 4DE,

J

J. Heffernan

EPSRC National Epitaxy Facility, University of Sheffield 2 , Sheffield S1 4DE,

M

M. S. Skolnick

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

A

A. M Fox

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,

L

L. R. Wilson

School of Mathematical and Physical Sciences, University of Sheffield 1 , Sheffield S3 7RH,