Researchers at Intel Corp. and the University of California, Berkeley are looking for ways to surpass existing transistor technology, paving the way for new memories and logic circuits that may appear in the future On every computer on earth.
On December 3, before the publication of "Nature", a paper was first published on the Internet. The article mentioned the application of multiferroic and topological materials to logic and memory devices. (Type metal-oxide-semiconductor) microprocessors have energy-saving improvements of 10 to 100 times.
Under the same conditions, the amount of logic operation of a magnetoelectric spin orbit (MESO) device will be five times that of a COMS device, and it will continue to develop in the direction of more calculation per unit area. This is a core principle of Moore's Law.
The new devices will drive the development of technologies with high computing power and low energy consumption, especially highly automated self-driving cars and drones, both of which require multiple computer operations per second.
Sasikanth Manipatruni, director of the MESO project at the Hillsborough Research Group in Intel Oregon, said, "As the development of CMOS technology matures, we have very powerful technology options to help us solve problems. In a way, new devices May continue to improve computing power. " Sasikanth Manipatruni was the lead author of this paper and designed the first MESO device.
Transistor technology was invented 70 years ago and is now used in mobile phones, appliances, automobiles, supercomputers and other fields. Transistors move electrons back and forth inside a semiconductor and store them as binary bits 0 and 1.
In new MESO devices, binary is defined as the upper and lower magnetic spin states of particles in a multiferroic material. Multiferroic materials were created in 2001 by Ramamoorthy Ramesh, a professor of materials science and engineering physics at the University of California, Berkeley. He is also the lead author of this paper.
Ramesh, also a researcher at the Lawrence Berkeley National Laboratory, said: "The study found that applying a voltage to multiferroic materials will change the magnetic order of the materials. But to me, what can these multiferroic materials do? It has always been a big problem. MESO solves this confusion and it provides a new way for the development of computers. "
In the journal Nature, researchers reported that they had reduced the voltage required to turn on multiferromagnetic switches from 3V to 0.5V, and predicted that it might drop to 0.1V in the future. This will be 1/5 or 1/10 of the voltage required for CMOS transistors currently used. Low voltage means low energy loss. The total energy from 1 to 0 is 1/10 to 1/30 of the energy required by COMS.
"Some key technologies need to be developed to meet new computing devices and architectures," said Manipatruni, who combined the capabilities of magnetoelectric and spin-orbit materials to come up with MESO. "We are trying to set off a wave of innovation in the industry and academia to see what the next transistor-like choice should look like."
IoT and artificial intelligence
Energy-efficient computers are urgently needed. The US Department of Energy predicts that as the computer chip industry expands to trillions of dollars over the next few decades, the energy consumption of computers may soar from 3% of current US energy consumption to 20%. Without energy-saving transistors, the combination of computers with everything-the so-called Internet of Things-will be hindered. Ramesh said that without new science and technology, the United States' lead in manufacturing computer chips could be surpassed by semiconductor manufacturers in other countries.
"Because of the application of machine learning, artificial intelligence and the Internet of Things, tomorrow's home, tomorrow's car, tomorrow's manufacturing capabilities will look very different," said Ramesh. Until recently, he was still a Berkeley Lab energy technology Deputy Director, "If we use existing technology and there are no new discoveries, energy consumption will be great, and we need new scientific breakthroughs."
Co-author Ian Young, Ph.D. at the University of California, Berkeley, formed a team with Intel Manipatruni and Dmitri Nikonov eight years ago to study transistor replacements. Five years ago, they started focusing on multiferroic and spin-orbiting materials, so-called "topological" materials with unique quantum properties.
"The analysis gave us this magnetoelectric material," Manipatruni said.
Multiferroic and spin-orbiting materials
A multiferroic material is a "collective state" material in which atoms can exhibit a variety of iron properties. For example, in a ferromagnet, the magnetic moments of all iron atoms in a material are aligned in a straight line to form a permanent magnet. On the other hand, the positive and negative charges of the atoms in the ferroelectric material cancel each other out, creating an electric dipole that runs through the material and forms a permanent electrical moment.
MESO is a multi-ferrous material composed of bismuth, iron, and oxygen (BiFeO3), which has magnetic and ferroelectric properties. Ramesh said that its biggest advantage is that the two states of magnetic and ferroelectricity are connected and coupled with each other, so changing one state will affect the other. By manipulating the electric field, you can change the state of the magnetic field, which is essential for MESO.
With the rapid development of topological materials with spin-orbit effects, MESO technology has made a key breakthrough. The spin-orbit effect can effectively read the state of multiferritic materials. In MESO devices, the electric field changes the dipole electric field in the material, and the dipole electric field changes the spin of the electrons that generate the magnetic field. This effect is called spin-orbit coupling, and is a quantum effect of a material. The direction of the electron's spin determines the current.
A paper published earlier this month in Science Advances states that the University of California, Berkeley and Intel Corporation have demonstrated experiments with voltage-controlled magnetic switches using the magnetoelectric material bismuth ferrite (BiFeO3), which is a MESO device implementation key.
"We are looking for revolutionary, rather than progressive, computational methods beyond the CMOS era," said Young. "Meso is built around low-voltage interconnects and low-voltage magnetoelectricity, bringing quantum material innovation to computing."
Other co-authors of this paper on Nature include Intel Corporation's Tanay Gosavi, Huichu Liu, and Bhagwati Prasad, Yen-Lin Huang, Everton Bonturim of the University of California, Berkeley. This work was done with the support of Intel Corporation.