Related Experiment Video
Updated: Jun 29, 2026
10:36
Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating
Published on: April 12, 2018
Electric-field-induced superconductivity in an insulator
K Ueno1, S Nakamura, H Shimotani
1WPI-Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan. uenok@imr.tohoku.ac.jp
Nature Materials
|October 14, 2008
Summary
Researchers achieved electric-field-induced superconductivity in an insulator using electric-double-layer gating. This method enhanced carrier density to 10^14 cm^-2, enabling a 2D superconducting state in strontium titanate.
Area of Science:
- Condensed matter physics
- Materials science
- Superconductivity
Background:
- Electric field control of charge carrier density is crucial for tuning material properties.
- Increasing maximum carrier density is key to inducing superconductivity in field-effect-transistor geometries.
- Previous experiments were limited by dielectric breakdown, restricting modulation to already conducting samples.
Purpose of the Study:
- To overcome limitations of dielectric breakdown in electric field control experiments.
- To achieve electric-field-induced superconductivity in an insulating material.
- To explore novel superconducting states using electric-double-layer gating.
Main Methods:
- Utilized electric-double-layer gating with an organic electrolyte.
- Applied gate voltages up to 3.5 V to a strontium titanate (SrTiO3) single-crystal channel.
- Enhanced sheet carrier density from zero to 10^14 cm^-2.
Main Results:
- Successfully induced superconductivity in an insulator (SrTiO3).
- Achieved a two-dimensional superconducting state below a critical temperature of 0.4 K.
- The critical temperature is comparable to bulk crystals, demonstrating the method's efficacy.
Conclusions:
- Electric-double-layer gating is a promising technique for inducing superconductivity in insulators.
- This method allows for significant enhancement of carrier density without dielectric breakdown.
- Opens new avenues for discovering unprecedented superconducting phenomena.
Related Concept Videos
01:24Superconductor
A substance that reaches superconductivity, a state in which magnetic fields cannot penetrate, and there is no electrical resistance, is referred to as a superconductor. In 1911, Heike Kamerlingh Onnes of Leiden University, a Dutch physicist, observed a relation between the temperature and the resistance of the element mercury. The mercury sample was then cooled in liquid helium to study the linear dependence of resistance on temperature. It was observed that, as the temperature decreased, the...
01:28Types Of Superconductors
A superconductor is a substance that offers zero resistance to the electric current when it drops below a critical temperature. Zero resistance is not the only interesting phenomenon as materials reach their transition temperatures. A second effect is the exclusion of magnetic fields. This is known as the Meissner effect. A light, permanent magnet placed over a superconducting sample will levitate in a stable position above the superconductor. High-speed trains that levitate on strong...
01:23Induced Electric Fields
The fact that emfs are induced in circuits implies that work is being done on the conduction electrons in the wires. What can possibly be the source of this work? We know that it’s neither a battery nor a magnetic field, as a battery does not have to be present in a circuit where current is induced, and magnetic fields never do any work on moving charges. The source of the work is in fact an electric field that is induced in the wires. For example, if a stationary conductor is placed in a...
01:20Electric Field Inside a Conductor
When a conductor is placed in an external electric field, the free charges in the conductor redistribute and very quickly reach electrostatic equilibrium. The resulting charge distribution and its electric field have many interesting properties, which can be investigated with the help of Gauss's law.
Suppose a piece of metal is placed near a positive charge. The free electrons in the metal are attracted to the external positive charge and migrate freely toward that region. This region then has...
Suppose a piece of metal is placed near a positive charge. The free electrons in the metal are attracted to the external positive charge and migrate freely toward that region. This region then has...
01:26Electric Field at the Surface of a Conductor
Consider a conductor in electrostatic equilibrium. The net electric field inside a conductor vanishes, and extra charges on the conductor reside on its outer surface, regardless of where they originate.
In the 19th century, Michael Faraday conducted the famous ice pail experiment to prove that the charges always reside on the surface of a conductor. The experimental set-up consists of a conducting uncharged container mounted on an insulating stand. The outer surface of the container is...
In the 19th century, Michael Faraday conducted the famous ice pail experiment to prove that the charges always reside on the surface of a conductor. The experimental set-up consists of a conducting uncharged container mounted on an insulating stand. The outer surface of the container is...
01:27Induced Electric Fields: Applications
An important distinction exists between the electric field induced by a changing magnetic field and the electrostatic field produced by a fixed charge distribution. Specifically, the induced electric field is nonconservative because it does not work in moving a charge over a closed path. In contrast, the electrostatic field is conservative and does no net work over a closed path. Hence, electric potential can be associated with the electrostatic field but not the induced field. The following...