AVS 70 Session QS-ThP: Quantum Science and Technology Mini-Symposium Poster Session

Transmon qubits are one of the leading technologies for quantum information science (QIS) with fabrication and characterization techniques accessible by numerous laboratories around the world.In recent years, efforts at coherence time optimization have shifted focus to the performance of the underlying superconducting material and accompanying surface oxides.While earlier devices were fabricated from Al and Nb, the current state-of-the-art transmons are fabricated from Ta with coherence times up to 0.5 milliseconds.Our research focuses on Ta coplanar waveguide (CPW) resonators fabricated by a damascene technique which yields pristine metal structures entrenched in silicon substrates.While the participation ratio of the dielectric substrate is increased, the device edges remain oxide free from the entrenchment and a nitride capping layer.Our recent studies revealed a current best Q value on the order of 105 at low power.This work, performed in collaboration with NY CREATES/SUNY Poly and BNL, will be discussed along with the prospect of further improvements.

Colloidal quantum dots (QDs) and rods (QRs) are promising quantum materials with unique electronic and optical properties for quantum science applications such as quantum computation, sensing, simulation, and communication. While colloidal QDs and QRs can be dispersed in solvents and readily integrated on surfaces and in devices using solution-based assembly techniques, scalable and deterministic arrangement of single and arrayed QDs/QRs on devices with sub-10 nm resolution remains a challenge. We employ robust DNA origami templates to guide the incorporation of colloidal QDs and QRs on device substrates with nanoscale precision.

DNA origami is a powerful platform for the precise assembly and organization of functional nanomaterials, enabling the creation of complex, tailor-made structures with unprecedented accuracy and programmability. While DNA-modified molecules and colloidal metallic nanoparticles are routinely assembled onto DNA origami, QDs and QRs have been challenging to incorporate due to low DNA conjugation efficiency. We have developed an ultrafast dehydration-assisted method to conjugate a dense layer of ssDNA onto QDs/QRs directly from organic solvent to facilitate their precise and stable assembly on DNA origami templates [1]. To arrange QR arrays on the surface, we developed a Surface-Assisted Large-Scale Assembly (SALSA) strategy to fabricate 2D DNA origami lattices tethered by unique crossover interactions directly on a solid substrate [1]. Alignment of the QRs in the 2D lattice was achieved through predefined binding strands linearly arranged on the origamis to unlock polarized light emission along the long axis of the arrayed QRs. To integrate DNA-templated QDs/QRs into chip-based photonic devices, we further employed lithography to guide the deterministic patterning of precisely positioned and oriented individual DNA origami templates on silicon chips. Landing pads of matching size and shape of the DNA origami were first fabricated using electron beam lithography, followed by origami placement through electrostatic interaction-guided self-assembly. QDs and QRs were then assembled onto the origami templates with predefined position and orientation. Our methods offer significant potential for the precise integration of high-quality colloidal QDs and QRs as quantum emitters for integrated quantum photonics.

1. Chen, C., Luo, X., Kaplan, A. E. K., Bawendi, M. G., Macfarlane, R. J., & Bathe, M. (2023). Science Advances, 9(32), eadh8508.

This poster covers a bit of metrology history of how we got to where we are today and gives a forward-looking vision for the future of measurement science and its important role in our daily lives. The role of NIST as a National Metrology institute (NMI) is briefly described considering the world-wide redefinition of units that occurred on May 20^th, 2019. The re-definition of units is now aligned with physical constants of nature and fundamental physics which opens new realization routes with quantum-based sensors and standards. The NIST on a Chip program (NOAC) is briefly introduced in this context.

The technical core is a deeper dive into research on measurement methods for pressure, the Fixed Length Optical Cavity (FLOC) and for vacuum the Cold Atom Vacuum Standard (CAVS). What is exciting about many of these new measurement approaches is that they are both primary (relying on fundamental physics), are quantum-based and use photons for the measurement readout which is key for taking advantage of the fast-growing field of photonics. The FLOC will enable the elimination of mercury barometers pressure standards worldwide and the CAVS will be first primary standard for making vacuum measurements below 1.3x10^-5 Pa. A Sensitive Photonic Thermometer (SPOT) will be introduced, along with other sensing technologies that the NOAC program is currently investigating such as flux, magnetic field, and mass and torque.