Phase-change memory is a type of random access memory (RAM) that works by exploiting the unique behavior of chalcogenide glass. PCM exhibits two stable phases – amorphous (without a clearly defined structure) and crystalline (with a defined structure), having low and high electrical conductivity respectively.
As digital memory is comprised of 0s and 1s, a ‘0’ can be programmed to be written in amorphous phase and ‘1’ in crystalline phase, or vice-versa. Read and write operations are performed by applying low and high voltages. This is the technology used by Blu-ray discs to store content.
Phase-change memory doesn’t lose data when switched off and can last up to 10 million write cycles. To put it in perspective, a USB flash drive lasts only about 3,000 write cycles.
Previously, scientists had demonstrated the ability to store 1 bit per cell. But this time, they managed to successfully store 3 bits per cell in a 64k-cell array, demonstrating the technology at the IEEE International Memory Workshop in Paris. The same was done at elevated temperatures and after 1 million endurance cycles.
IBM Research’s manager of non-volatile memory research Dr. Haris Pozidis said that reaching 3 bits per cell is a significant milestone, because at this density the cost of phase-change memory will be significantly less than DRAM and closer to flash memory.
This breakthrough in phase-change memory has the potential of revolutionizing gadgets like PCs and smartphones. It can be embedded in mobile devices to store the operating system and firmware, enabling them to boot up in seconds. The technology holds promise for the enterprise sector as well. Large databases could be stored in phase-change memory based storage solutions for extremely fast query processing and data retrieval, such as in case of financial transactions.
Phase-change memory might just prove to be the next big innovation that future generation of smart devices need.