Rice University researchers have found a method to harness the recently identified “new terahertz gap” using strontium titanate, which opens up the possibility to create advanced optical technologies within the 3-19 terahertz frequency range. This breakthrough could lead to progress in quantum material applications and medical diagnostic tools.
The qualities of metal oxide could make it possible to utilize a broad spectrum of terahertz frequency photonics.
Visible light, which is only a small part of the electromagnetic spectrum, has already led to technologies like cell phones and CT scans due to the manipulation of light waves at frequencies beyond what human eyes can see.
The team at Rice University aims to exploit a previously untapped section of the spectrum.
The research includes three samples of ultrafast terahertz field concentrators developed by graduate student Rui Xu at Rice University’s Emerging Quantum and Ultrafast Materials Laboratory. The bottom layers, visible as white squares, consist of strontium titanate with specially patterned concentrator structures, which can be seen as a fine-grained pattern of dots with the naked eye. (Photo credit: Gustavo Raskosky, with additional inset by Rui Xu/Rice University)
Identifying the Spectrum’s Gap
There’s a significant gap in mid- and far-infrared light, covering the 5-15 terahertz frequencies and 20-60 micrometer wavelengths, where no efficient commercial products exist compared to other optical frequencies and radio frequencies, as described by Rui Xu, a third-year doctoral student at Rice and the lead author of an article in the journal Advanced Materials.
The study took place in the Emerging Quantum and Ultrafast Materials Laboratory, under co-author Hanyu Zhu, William Marsh Rice Chair and assistant professor of materials science and nanoengineering.
An illustration demonstrates how a quantum paraelectric lens focuses light pulses within the 5-15 terahertz range, involving conversion through ring-shaped polymer gratings and disk resonators on a strontium titanate substrate.
The Importance and Challenges of the Terahertz Gap
Optical technologies in this frequency area, sometimes referred to as “the new terahertz gap,” could have great value in studying and building quantum materials for room-temperature quantum electronics and for sensing in medical diagnostics, according to Zhu. Finding the appropriate materials for this terahertz gap has been a major hurdle, as such light usually reacts strongly with most materials, leading to rapid absorption.
Zhu’s team has managed to use strontium titanate to overcome this problem, enabling the creation of new particles called phonon-polaritons. Strontium titanate is effective across the entire 5-15 terahertz gap due to a quality known as quantum paraelectricity.
The researchers have demonstrated the potential of these devices in the 7-13 terahertz frequency range by designing ultrafast field concentrators. These concentrators intensify the light pulse, resulting in a powerful transient electric field of almost a gigavolt per meter.
Future Implications and Applications
This electric field is so potent that it could alter the materials’ structure to introduce new electronic characteristics or create a novel nonlinear optical response from small amounts of specific molecules, detectable through standard optical microscopes. Zhu believes their methodology could be applied to various commercially available materials, potentially enabling photonics devices in the 3-19 terahertz range.
The research paper, titled “Phonon Polaritonics in Broad Terahertz Frequency Range with Quantum Paraelectric SrTiO3” by Rui Xu et al., was published on 19 June 2023 in Advanced Materials.
Other contributors to the paper include researchers in materials science and nanoengineering, and students from Rice University and Texas A&M University.
The study received support from the National Science Foundation and the Welch Foundation.
Table of Contents
Frequently Asked Questions (FAQs) about fokus keyword: terahertz technology
What have Rice University researchers discovered in the field of terahertz technology?
They have identified a way to utilize the “new terahertz gap” using strontium titanate, enabling development in the 3-19 terahertz range. This could lead to advancements in quantum materials and medical diagnostics.
What material was used in this discovery, and why is it significant?
The researchers used strontium titanate, an oxide of strontium and titanium. Its atoms couple with terahertz light, forming phonon-polaritons, and it works across the entire 5-15 terahertz gap due to a property called quantum paraelectricity.
How does this discovery affect optical technologies?
The unlocking of the “new terahertz gap” opens up possibilities to create advanced optical technologies in the 3-19 terahertz range. It also has potential implications for room-temperature quantum electronics and sensing in biomolecules for medical diagnosis.
What are phonon-polaritons, and how do they relate to this research?
Phonon-polaritons are new particles formed when the atoms of strontium titanate couple with terahertz light. They are confined to the surface of the material and enable the efficient capture of light within the 5-15 terahertz gap, essential to this research.
How might this discovery impact medical diagnostics?
The potential use of optical technologies in the “new terahertz gap” frequency could enhance the sensing of functional groups in biomolecules, enabling advancements in medical diagnostics.
What is the role of quantum paraelectricity in this discovery?
Quantum paraelectricity is a property of strontium titanate that allows it to work across the entire 5-15 terahertz gap. Its atoms exhibit large quantum fluctuations and vibrate randomly, effectively capturing light without being self-trapped, even at zero degrees Kelvin.
Who supported this research?
The research was supported by the National Science Foundation and the Welch Foundation.
More about fokus keyword: terahertz technology
- Rice University’s Official Website
- The Journal Advanced Materials (where the research article was published)
- National Science Foundation’s Official Website
- Welch Foundation’s Official Website
4 comments
thats some next level discovery, rice university is always up to something big! cant wait to see where this leads. medical diagnostics advancements? count me in
Quantum what now? Its all Greek to me. But if it helps in medical stuff then its got to be good right?
Wow, this is really impressive. quantum materials are the future, and it looks like we’re getting closer. Terahertz tech sounds fascinating – need to look more into it!
strontium titanate… that’s a mouthful. i read somewhere about phonon-polaritons, but this is really breaking it down. great stuff, go science!