Original source: Materials Today
The quest for ever-smaller electronic components led an international group of researchers to explore using molecular building blocks to create them. These building blocks are based on DNA, which is able to self-assemble into arbitrary structures, but for use in nanoelectronic circuits these DNA structures need to be converted into highly conductive wires.
Inspired by previous works using the DNA molecule as a template for superconducting nanowires, the group took advantage of a recent bioengineering advance known as DNA origami to fold the DNA into arbitrary shapes.
In a paper in AIP Advances, researchers from Columbia University, Brookhaven National Laboratory, Bar-Ilan University in Israel and Ludwig-Maximilians-Universität München in Germany describe how to exploit DNA origami as a platform for building superconducting nanoarchitectures. The structures they built are addressable with nanometric precision and can be used as a template for 3D architectures that are impossible to create with conventional fabrication techniques.
The group’s fabrication process involves a multidisciplinary approach, namely the conversion of the DNA origami nanostructures into superconducting components. These nanostructures are created from two different types of DNA: a circular single strand as the scaffold, and a mix of complementary short strands acting as staples to fold the circular strand into the nanostructure.
“In our case, the structure is an approximately 220nm-long and 15nm-wide DNA origami wire,” said Lior Shani of Bar-Ilan University. “We dropcast the DNA nanowires onto a substrate with a channel and coat them with superconducting niobium nitride. Then we suspend the nanowires over the channel to isolate them from the substrate during the electrical measurements.”
The group’s work shows how to exploit the DNA origami technique to fabricate superconducting components that can be incorporated into a wide range of architectures.
“Superconductors are known for running an electric current flow without dissipations,” said Shani. “But superconducting wires with nanometric dimensions give rise to quantum fluctuations that destroy the superconducting state, which results in the appearance of resistance at low temperatures.”
By using a high magnetic field, the group suppressed these fluctuations and reduced about 90% of the resistance. “This means that our work can be used in applications like interconnects for nanoelectronics and novel devices based on exploitation of the flexibility of DNA origami in fabrication of 3D superconducting architectures, such as 3D magnetometers,” said Shani.