Halogen Lamps are dimmable. Halogen lamps can be dimmed by regular incandescent dimmers. You need to use line voltage (120V) halogen bulbs for this purpose.
Are Halogen Lamps Dimmable?
Not a feature of these high temperature bulb type. They are either on or off no dimming possible. Talk to a seller of the efficient light source and find out their capailites firsthand.