In 2024, the number of emails sent will be approximately 361 billion each day. Daily data creation has reached 328.77 million terabytes of data. In fact, 90% of global data was created in the last two years alone. And for this, large centers will be needed to store the information. The problem is the power consumption: it is too high.
Now a team of scientists from the University of Pennsylvania has overcome an important barrier to facilitate the adoption of next-generation data storage technologies. Thanks to the use of a unique material called indium selenide (In2Se3), those responsible for the advance ensure in a article published in Naturehaving discovered a technique to reduce the power requirements of phase change memory (PCM), a technology capable of storing data without a constant power supply, up to a billion times.
The breakthrough is a step toward overcoming one of the biggest challenges in PCM data storage, potentially paving the way for low-power electronics and memory devices, according to the study. PCM is a leading candidate for universal memory: computing memory that It can replace both short-term memory such as random access memory (RAM) and storage devices such as solid state drives (SSD) or hard drives.
RAM is fast, but needs significant physical space and a constant power supply to operate, while SSDs or hard drives are much denser and can store data while computers are turned off. Universal memory combines the best of both. It works by alternating materials between two states: crystalline, where the atoms are arranged in an orderly fashion, and amorphous, where the atoms are arranged randomly. These states map to binary 1s and 0s, encoding the data via switches in the states.
However, the “fusion-extinction technique” used to cycle these states, which involves rapidly heating and cooling PCM materials, requires significant energy, making the technology expensive and difficult to scale.
In their study, the team led by Ritesh Agarwal, professor of materials engineering, points to a way to completely avoid the fusion-extinction process, instead inducing amorphization through an electrical charge. Amorphization is basically create atomic disorder in the material to improve its performance. This dramatically reduces PCM power requirements and potentially opens the door to broader commercial applications.
“One of the reasons phase change memory devices have not reached widespread use is due to the energy required – explains Agarwal in a statement -. The potential of these findings for designing low-power memory devices is tremendous”.
The discovery is based on the unique properties of indium selenide, a semiconductor material with both “ferroelectric” and “piezoelectric” characteristics. Ferroelectric materials can spontaneously polarize, which means that They can generate an internal electric field without the need for an external charge. Piezoelectric materials, on the other hand, physically deform when exposed to an electrical charge.
When testing the material, the authors observed that some sections of it amorphized when exposed to a direct current. What’s more, this happened completely by chance.
“In fact, I thought it might have damaged the cables,” adds study co-author Gaurav Modi. Normally, electrical pulses would be needed to induce any type of amorphization, and here a direct current had altered the crystal structure, which should not have happened“.
Further analysis revealed a chain reaction triggered by the properties of the semiconductor. This begins with small deformations in the material caused by the current that triggers an “acoustic pull,” a sound wave similar to seismic activity during an earthquake. This then travels through the material, spreading amorphization across micron-scale regions in a mechanism the researchers compared to an avalanche gaining momentum.
The researchers explained that several properties of indium selenide, including its two-dimensional structure, ferroelectricity and piezoelectricity, work together to enable an ultra-low energy pathway for shock-triggered amorphization. This could sit the bases for future research around “new materials and devices for low-consumption photonic and electronic applications.” – concludes Agarwal -. “This opens a new field on the structural transformations that can occur in a material when all these properties are combined.”