Physicists Observed a New Kind of Transition in Electronic Crystals

The temperature changes can result in phase transitions in materials – like when water solidifies as ice in the cold. The temperature that triggers the difference depends on whether the material is cooling down or warming up. This is known as a hysteresis loop, and researchers think they’ve discovered a weird and entirely new example of this phenomenon.

Through such a lab setup, scientists spotted that the hysteresis loop for EuTe4 covered an enormous temperature range of at least 400 Kelvins – far more than the usual range for a Crystals solid like this, which would usually only be in the tens of Kelvins at most.

This finding immediately caught our attention, and our combined experimental and theoretical characterization of EuTe4 challenges conventional wisdom on the type of hysteretic transitions that can occur in Crystals. The research got curiouser and curiouser from there. There was no change in the electronic or lattice structure in the material across the temperature range that was measured, which again isn’t how phase transitions in Crystals should work.

While it’s early days for this discovery, the team does have a few ideas about what might be happening: the particular way electrons are arranged in EuTe4 causes a secondary electronic Crystals to form, and it could be that as this second layer moves and shifts, it creates different configurations in the hysteresis loop.The experiments showed that the researchers were able to significantly vary the electrical resistance of the material by cooling down or warming up the Crystals – another indication of something strange and unexpected going on.