Chiral control of excitons: infra-red circular polarized emission in carbon nanotubes through chiral defect chemistry

The National Science Foundation Division of Chemistry awarded North Dakota State University $719,997 on September 1, 2026, under the Mathematical and Physical Sciences program (CFDA 47.049) to investigate chiral control of excitons and infrared circular polarized emission in carbon nanotubes through chiral defect chemistry.

The project combines computational modeling, chemical synthesis, and optical experiments to discover design rules for engineering carbon-based nanomaterials with tunable chiral optical response. The research focuses on how molecules attached to nanotubes create chiral defect sites that control the handedness of emitted photons in the near-infrared spectral region. Single-photon emitters operating at room temperature in this region support quantum communication over optical fiber networks and enable enhanced biomedical imaging and sensing. By adding control over photon handedness, the work creates new methods to encode and manipulate optical information for quantum technologies, secure quantum communication, and chiral biochemical sensing. Educational and outreach activities engage students nationwide in emerging quantum and nanotechnology research.

Period of performance runs from September 1, 2026, through August 31, 2029. Work is performed in Fargo, North Dakota.

Abstract

This project aims to discover new ways to control the chirality, or handedness, of light emitted by carbon nanotubes (cnts). Just as our left and right hands are mirror images that cannot be superimposed, many molecules exist in left- and right-handed forms, a property known as chirality. Chiral molecules respond differently to left- and right-handed circularly polarized light, making chirality fundamental to chemistry, biology, medicine, and quantum technology. By combining calculations with chemical synthesis and optical experiments, the team will investigate how molecules attached to the nanotube create chiral defect sites that control the handedness of the emitted light (photons). These efforts will establish new design rules for engineering chemically tunable carbon-based nanomaterials with chiral optical response. Cnts provide a unique platform for this research because engineered defects can transform them into bright single-photon emitters that operate at room temperature in the near-infrared (NIR) spectral region. Single photons are a fundamental building block of quantum technology carrying quantum information with exceptional security. Because NIR photons travel efficiently through optical fiber networks with minimal signal loss, cnts are promising materials for quantum communication. NIR light also penetrates deeply into biological tissue, enabling improved biomedical imaging and sensing. Adding control over the handedness of emitted photons will provide a new way to encode and manipulate optical information, opening opportunities for next-generation quantum technologies, secure quantum communication, and improved selectivity in chiral biochemical sensing. Educational and outreach activities will broaden participation in stem by engaging students nationwide in emerging quantum and nanotechnology research. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the foundation's intellectual merit and broader impacts review criteria.- subawards are planned for this award.