Temporal vortex
A temporal vortex is an artificially-generated rift in the spacetime continuum, which allows for travel from one point in spacetime to another. Temporal vortices have been known to have been used by species such as the Devidians and the Borg.

In 2368, the crew of the  discovered that the Devidians were using a temporal vortex to travel back in time to Earth, the year 1893, to harvest Human neural energy for sustenance. The vortex was formed by using an ophidian-like creature to create minute distortions in the spacetime continuum, and then using massive amounts of triolic waves to focus it to a specific time and place. While investigating on the planet Devidia II, Lieutenant Commander Data was inadvertantly pulled into the vortex, arriving in the 19th century. The rest of the Enterprise command crew, except for Lieutenant Worf, eventually followed, and were able to rescue Data. Returning through the vortex to the 24th century, they were able to destroy the Devidians' compound using a series of specially-modified photon torpedoes. ()

In 2373, a Borg sphere generated a temporal vortex to the year 2063, through the controlled emission of chronometric particles. Pursuing the sphere, the  became caught in a resultant temporal wake, which had the effect of insulating the Enterprise from the changes in the timeline effected by the Borg. Scanning Earth, the Enterprise crew found that, in the new timeline, humanity had been assimilated, and realized that they had to follow the sphere through the rift in order to correct the damage done to history. Later, after having successfully restored the timeline, Commander Geordi La Forge was able to reconfigure the Enterprises warp field to match the chronometric readings of the sphere, thereby recreating the vortex and allowing the ship to return to its own time. ()

See also
Spatial vortex
Time vortex
Temporal rift

fr:Vortex temporel
Time travel