Researchers at the National Institute of Standards and Technology (NIST) have developed a method to improve the reliability of quantum information technologies, biological imaging, and more by aligning quantum dots with the center of photonic components with high precision. This alignment is crucial for chip-scale devices that utilize the radiation emitted by quantum dots for storing and transmitting quantum information. The researchers achieved an alignment error of 10 to 20 nanometers across the entire image from an optical microscope, allowing for the correction of many individual quantum dots.
In a typical measurement scenario, researchers use an optical microscope to locate individual quantum dots on a semiconductor material, but errors can accumulate due to various factors such as semiconductor shrinkage at low temperatures. The NIST method corrects these errors by creating two types of traceable standards for calibrating optical microscopes, one at room temperature to analyze the fabrication process and the other at cryogenic temperatures to measure quantum dot positions. By accurately measuring the positions of features in fabricated standards, errors from magnification calibration and image distortion are identified and corrected.
The NIST research team worked on calibrating the magnification of cryogenic optical microscopes used for imaging quantum dots, highlighting the challenges posed by image distortion at low temperatures. Image distortions can lead to errors in determining the position of quantum dots and aligning them within light-controlling devices. To address this, the researchers developed a detailed model of measurement and fabrication errors in integrating quantum dots with chip-scale photonic components, identifying the potential for a hundred-fold improvement in device performance.
The development of traceable standards and calibrations at NIST could extend beyond quantum-dot devices to improve accuracy and reliability in other applications of optical microscopy, such as imaging brain cells and mapping neural connections. These applications require precise positioning of objects across entire microscope images and coordination of position data from different instruments at varying temperatures. The research team at NIST aims to enhance the efficiency of lab-to-fab transitions by addressing measurement and fabrication errors that limit the performance of devices using quantum dots.
By creating standards that are traceable to the International System of Units (SI) for optical microscopes, the NIST researchers have paved the way for improved alignment of quantum dots with photonic components, ultimately enhancing the performance and reliability of quantum information technologies. Their work represents a significant advancement in the development of high-performance devices that can transition from research laboratories to commercial products more efficiently. Through detailed calibration methods and error correction, the NIST team has demonstrated the potential for a hundred-fold improvement in the functionality of quantum-dot devices, opening up new possibilities for a wide range of applications in quantum information processing and biological imaging.
