High-Temp Semiconductor With a Twist, Please

There’s a new way to make and manipulate a class of high-temperature semiconductors, and an international team, including Rutgers University–New Brunswick, is front and center of the process. The result could be the ability to create unusual forms of superconductivity in previously unattainable materials.

When cooled, superconductors can conduct electricity without resistance or energy loss. Most superconductors exhibit this capability at temperatures a few degrees above absolute zero, so they’re impractical.

Experiments that grew out of theoretical calculations are now published in Science and confirm predictions by Pixley and Pavel Volkov representing the underlying quantum physical behavior and project how cuprate superconductors behave if placed in proximity in specific configurations and at varying angles.

The new experiments were conducted by a team at Harvard University led by professor and physicist Philip Kim, taking two cuprate superconductors, placing them together and twisting them precisely.  The result is a unique new superconductor, which is promising for the world’s first high-temperature, superconducting diode. The device could fuel fledgling industries such as quantum computing that rely on fleeting phenomena produced in materials like superconductors.

The research extends the field of “twistronics,” which involves twisting flat layers of two-dimensional materials to produce physical effects at the subatomic level that are observable on the macroscopic scale.

The experimentalists first split an extremely thin film of a superconductive cuprate, called “BSCCO,” made of bismuth strontium calcium copper oxide, into two layers. Maintaining frigid conditions, they stacked the layers at a 45-degree twist, retaining superconductivity at the fragile interface.