Researchers from École Polytechnique Fédérale de Lausanne (EPFL) have discovered that vanadium dioxide (VO2) is capable of "remembering" the entire history of previous external stimuli.
Vanadium dioxide marks the first material EPFL researchers have discovered that identified as possessing this property.
The study was published in Nature today.
Mohammad Samizadeh Nikoo, a Ph.D. student at EPFL's Power and Wide-band-gap Electronics Research Laboratory (POWERlab), made a chance discovery during his research on phase transitions in vanadium dioxide (VO2).
As per the study, VO2 has an insulating phase when relaxed at room temperature and undergoes a steep insulator-to-metal transition at 68 °C, where its lattice structure changes.
Under normal conditions, VO2 displays volatile features. "The material reverts to the insulating state right after removing the excitation," said Mohammad Samizadeh Nikoo.
During the experiment, Samizadeh Nikoo applied electric current to a sample of VO2. "The current moved across the material, following a path until it exited on the other side," he said.
After the current passed in the first application, the material returned to its state, and after the second application of Samizadeh Nikoo, the material began to show "remembering" features.
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