To elaborate a bit on what Intruder wrote:
The wing tip vortex is, in very simple terms, the high pressure air below the wing trying to displace the low pressure air above the wing. Since it's the difference in air pressure between the top and bottom of the wing that creates lift, although there are various methods of disguising or decreasing the strength of that vortex (e.g. winglets), as long as the wing is creating lift the vortex will exist. The greater the lift, the greater the pressure differential between the top and the bottom of the wing, and the stronger the resultant vortex. So, as a general rule, the heavier the aircraft, the stronger the vortex.
To your specific example, jet wakes dissipate fairly quickly - even at takeoff thrust, the jet wake will be down to around 35 knots only 300 meters (1000 ft.) behind the aircraft. The wing tip vortices can take upward of a minute to dissipate to a safe level.