In a 2006 study, this effect was observed in vortex-forming Bose-Einstein condensates confined to anisotropic traps.  One device that displays this effect is simply a circuit with positive feedback and a loop gain greater than 1, while another device can be formed by having 
In a 2006 study, this effect was observed in vortex-forming Bose-Einstein condensates confined to anisotropic traps.  One device that displays this effect is simply a circuit with positive feedback and a loop gain greater than 1, while another device can be formed by having a solenoid operate a ratchet-and-cam.  Besides Schmitt triggers and latching relays, this effect described by the Preisach model is shown in the relaxor variant of one type of material, which displays a "slim" variant of this effect. Another variant is seen in ice structuring proteins, a thermal variant notably displayed by agar, which melts at 85 degrees Celsius but freezes at 40 degrees.  FTP, name this effect also seen in ferromagnets, in which a system shows a lag between input and output by displaying physical memory.
In a 2006 study, this effect was observed in vortex-forming Bose-Einstein condensates confined to anisotropic traps.  
hysteresis effect