The ability to measure electric current precisely is crucial in a number of fields, from enhancing medical diagnostics, advancing quantum computing, refining electronic and nanotechnology manufacturing, to improving scientific research. Precise micro-current measurements enable the development of more reliable electronic devices, sensitive medical equipment, and robust scientific instruments, helping to foster innovation and understanding in technology, healthcare, and environmental monitoring, and paving the way for breakthroughs in fundamental science and industry applications.

Researchers from the Japanese National Institute of Advanced Industrial Science and Technology (AIST) and NTT Corporation recently succeeded in measuring the small currents produced by silicon quantum dot devices, taking a step towards setting new standards for measuring quantum currents. A silicon quantum dot is a tiny particle, typically ranging in size from a few to several hundred nanometers (a nanometer is one billionth of a meter).

Silicon quantum dots, which can individually manage the flow of electrons, are at the center of the partners' innovation. Silicon quantum dots control electron flow by confining electrons within nanometer-sized spaces, creating discrete energy levels. This quantum confinement allows precise manipulation of electronic properties, making the dots useful in areas requiring controlled electron movement. AIST and NTT researchers were able to control two different silicon quantum dots to each transport 1 billion electrons every second and their precise handling led to both devices producing a constant current of the same magnitude. The precision they achieved is worth noting: of the 1 billion electrons carried per second in each device, there were only 400 differences between the devices. Or to put it another way: the world's most accurate current.

AIST and NTT's achievement opens up a number of potential applications across multiple industries:

1. Higher Medical Equipment Accuracy: Medical devices that measure tiny biological currents, such as those in nerve cells or in the brain, could become more accurate.

2. Better Microchip Manufacturing: In the production of microchips and semiconductors, controlling and measuring minuscule currents is crucial. This technology could lead to the development of more precise and powerful microchips.

3. Quantum Computing: The precise control and measurement of electric currents at the quantum level could aid the development and improvement of quantum computers.

4. More Accurate Chemical Sensing and Analysis: Tiny currents can indicate the presence of specific molecules or chemical reactions. This technology could lead to more sensitive and accurate sensors for detecting pollutants, monitoring industrial processes, or even conducting forensic investigations.

5. More Precise Scientific Instruments: Many scientific research fields rely on the measurement of very small currents to understand phenomena at the atomic or molecular level. The ability to measure these tiny currents with high precision could improve the accuracy of experiments in physics, chemistry, and materials science, leading to new discoveries and advancements.

Looking forward, AIST and NTT aim to work with multiple devices at the same time to develop a new standard for measuring electric current. This new method would work by precisely controlling individual electrons. The research partners intend that their work could be integrated with existing standards for measuring electrical resistance and voltage. If successful, they would help improve our understanding of basic physics principles by demonstrating that these principles remain consistent even when observed on a very small, microscopic scale.

NTT—Innovating the Future

Daniel O'Connor

Daniel O'Connor joined the NTT Group in 1999 when he began work as the Public Relations Manager of NTT Europe. While in London, he liaised with the local press, created the company's intranet site, wrote technical copy for industry magazines and managed exhibition stands from initial design to finished displays.

Later seconded to the headquarters of NTT Communications in Tokyo, he contributed to the company's first-ever winning of global telecoms awards and the digitalisation of internal company information exchange.

Since 2015 Daniel has created content for the Group's Global Leadership Institute, the One NTT Network and is currently working with NTT R&D teams to grow public understanding of the cutting-edge research undertaken by the NTT Group.