The United States has developed a new ultra-thin superconducting field effect transistor


According to the report of the American Physicists Organization Network on April 28 (Beijing time), American scientists have constructed an ultra-thin superconducting field-effect transistor using self-designed and precise atomic layer-by-layer technology to gain insight into the changes in insulating materials. The environmental details of the high-temperature superconductor. The breakthrough, published in the journal Nature on the same day, will enable scientists to better understand high-temperature superconductivity and accelerate the development of resistance-free electronic devices.

Under what circumstances does the common insulating material copperate transition from an insulated state to a superconducting state? What happens when this transition occurs? These problems have always troubled physicists. One way to explore this transition is to apply an external electric field to increase or decrease the free electron concentration in the material and observe its effect on the material's ability to load current. But to do this in cuprate superconductors, you also need to build ultra-thin films with a consistent composition and an electric field of up to 10 billion volts / meter.

The Brookhaven Thin Film Research Group, led by the US Department of Energy physicist Ivan Borovich, previously used molecular beam epitaxy technology to make this superconducting thin film. This technology can also accurately control each atomic layer at a time. The thickness of the layer. They recently demonstrated that a single layer of keto salt can exhibit undecayed high-temperature superconductivity in the thin film produced by molecular beam epitaxy. They used this method to produce an ultra-thin superconducting field effect transistor.

Inside the standard field-effect transistor that is the basis of all modern electronic devices, a semiconductor material carries current from the “source” electrode at one end of the device to the “consumer” electrode at the other end; a thin insulator serves as the third electrode “gate” electrode Control field effect transistors. When a specific gate voltage is applied to the insulator, the gate electrode will open or close. However, there is no known insulator that can withstand the high electric field required to induce high-temperature superconductivity within the keto salt. Therefore, the design of standard field-effect transistors is not suitable for high-temperature superconducting field-effect transistors.

The Borovich team used a conductive liquid electrolyte to separate the charge. When an external voltage is applied to the electrolyte, the positively charged ions in the electrolyte move toward the negative electrode, and the negatively charged ions move toward the positive electrode, but when they reach the electrode, the ions will suddenly stop moving, just like hitting the "South Wall". The electric field between equal opposite charges carried by the electrode "wall" can exceed 10 billion volts / meter.

In the newly developed superconducting field effect transistor, the critical temperature of the high-temperature superconductor compound model (lanthanum-strontium-copper-oxygen) can reach about 30 degrees Kelvin, which is 80% of its maximum value, which is 10 times the previous record. Scientists can use this transistor to study the basic principles of physics related to high temperature superconductivity.

Superconducting field effect transistors have a wide range of applications. Semiconductor-based field-effect transistors consume large amounts of energy, while superconductors have no resistance and no energy consumption. In addition, the ultra-thin structure made by the arrangement of atoms layer by layer also allows scientists to better use the external electric field to control superconductivity.

Borovich said that this is just the beginning. There are still many secrets of high-temperature superconductors to be explored. As its mysterious "veil" is unveiled one by one, ultra-fast and energy-saving high-temperature superconductors can be manufactured in the future.