Embarking on Quest for New Quantum Materials

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Current approaches for quantum computing, sensing, communications, and signal-processing rely on superconducting electronic devices that can manipulate or process information at quantum levels of precision. Due to the fragile nature of quantum mechanical processes, these devices need to be cooled to a fraction of a degree above absolute zero (-273 C / -460 F). This requires large refrigeration units that draw significant electrical power, limiting the scalability of current technology to achieve more robust quantum computing and sensing devices.

DARPA’s new Synthetic Quantum Nanostructures (SynQuaNon) program aims to address this challenge with a fundamental science effort that seeks to develop synthetic metamaterials to enable enhanced functionalities and novel capabilities for quantum information science. The program will explore new manmade materials (such as metamaterials, nano patterned structures, and quantum heterostructures) that allow for higher operating temperatures to significantly reduce size, weight, and power (SWaP) requirements. The program calls for demonstrating the new quantum materials in functional devices of relevance to quantum information science applications.

“If we can increase the operating temperature for new superconducting nanoelectronic devices by a factor of 10, for example, the size of the refrigerator required for cooling goes down by more than a factor of 100,” said Dr. Mukund Vengalattore, program manager in DARPA’s Defense Sciences Office. “By reducing the power and cooling overhead required, we can reduce the SWaP significantly as well as improve other device-relevant metrics.”

With SynQuaNon, Vengalattore emphasizes a focus beyond lab development, demonstrating metamaterials on testable devices.

“The goal is to produce a material that is device friendly, that can be plugged directly into all sorts of applications,” said Vengalattore. “In essence, the questions we are asking within SynQuaNon are: ‘Can we create synthetic materials that can enhance or tune specific properties – like the superconducting temperature? Can we incorporate such synthetic materials within superconducting devices for better performance or new capabilities for quantum information science?’”

If SynQuaNon is successful, advances could include more stable superconducting quantum bits (qubits), which would benefit the quantum computing community by allowing state-of-the art quantum computers to scale to larger sizes. Novel synthetic nanomaterials could also allow for single-photon detectors to operate at higher temperatures or faster response rates, enabling detection of a single photon (the quantum limit of light) with increasing speed. Single-photon detectors are useful for quantum computing applications where information is stored in a single photon, but they’re also useful for a host of scientific and defense applications requiring precise detection of very dim objects. A third potential application area is general RF (radio frequency) amplification devices. Some electronic radio frequency devices, called superconducting parametric amplifiers, operate at very low temperatures and are also limited by the inherent physical properties of existing superconductors. By modifying these properties with materials engineering approaches in SynQuaNon, these RF amplifiers could be made smaller and more inexpensively, and they could operate at higher temperatures with less noise.

The SynQuaNon program builds on the recently released Disruption Opportunity (DO) by the same name. The DO focuses on developing theory and modeling and making predictions to inform the full program. The full SynQuaNon program is focused on experimental demonstration and device testing and validation.