Using density matrix equations of motion, we predict a femtosecond collective spin tilt triggered by nonlinear, near-ultraviolet (∼3eV), coherent photoexcitation of (Ga,Mn)As ferromagnetic semiconductors with linearly polarized light. This dynamics results from carrier coherences and nonthermal populations excited in the {111} equivalent directions of the Brillouin zone and triggers a subsequent uniform precession. We predict nonthermal magnetization control by tuning the laser frequency and polarization direction. Our mechanism explains recent ultrafast pump-probe experiments.PACS numbers: 78.47. 78.20.Ls, 78.47.Fg, 42.50.Md Long range magnetic order arises from the interactions between itinerant and localized spins in a wide variety of systems, such as EuO, EuS, chrome spinels, pyrochlore, manganese oxides, or (III,Mn)V ferromagnetic semiconductors [1,2]. With ferromagnetic semiconductors one can envision multifunctional devices combining information processing and storage on a single chip with low power consumption. Fast spin manipulation is of great importance for such spin-electronic, spin-photonic, magnetic storage, and quantum computation applications.One of the challenges facing magnetic devices concerns their speed. The magnetic properties of carrier-induced ferromagnets respond strongly to carrier density tuning via light, electrical gates, or current [3]. While magnetic field pulses and spin currents can be used to manipulate spin on the many-picosecond time scale, femtosecond spin manipulation requires the use of laser pulses [4,5]. In ultrafast pump-probe magneto-optical spectroscopy, the pump optical pulse excites e-h coherences and corresponding carrier populations, whose subsequent interactions trigger a magnetization dynamics monitored as function of time via the Faraday or Kerr rotation [6].The physical processes leading to femtosecond magnetization dynamics (femto-magnetism) are under debate. Open questions include the possibility of direct photonspin coupling, the distinction of coherent and incoherent effects, and the exact role of the spin-orbit interaction. Following the pioneering work of Ref. [7], many ultrafast spectroscopy experiments were interpreted in terms of a decrease in the magnetization amplitude due to transient thermal effects [7,8]. Observations of lightinduced changes in the magnetization orientation were also mostly attributed to the temperature elevation, which leads to transient changes in the magnetic easy axes [9,10,11]. Most desirable is nonthermal magnetization control within the femtosecond coherent [12] temporal regime, which promises more flexibility limited only by the optical pulse duration. Experiments in ferrimagnetic garnets were interpreted in terms of an interplay between the inverse Faraday effect [13] and long-lived changes in the magneto-crystalline anisotropy [4]. In (Ga,Mn)As, Ref.[14] reported magnetization precession triggered by changes of magnetic anisotropy on a ∼100ps time scale due to carrier relaxation, while Ref.[15] demonstrated coherent ...