  Turbulence profoundly affects particle transport and plasma heating in many
astrophysical plasma environments, from galaxy clusters to the solar corona and
solar wind to Earth's magnetosphere. Both fluid and kinetic simulations of
plasma turbulence ubiquitously generate coherent structures, in the form of
current sheets, at small scales, and the locations of these current sheets
appear to be associated with enhanced rates of dissipation of the turbulent
energy. Therefore, illuminating the origin and nature of these current sheets
is critical to identifying the dominant physical mechanisms of dissipation, a
primary aim at the forefront of plasma turbulence research. Here we present
evidence from nonlinear gyrokinetic simulations that strong nonlinear
interactions between counterpropagating Alfven waves, or strong Alfven wave
collisions, are a natural mechanism for the generation of current sheets in
plasma turbulence. Furthermore, we conceptually explain this current sheet
development in terms of the nonlinear dynamics of Alfven wave collisions,
showing that these current sheets arise through constructive interference among
the initial Alfven waves and nonlinearly generated modes. The properties of
current sheets generated by a strong Alfven wave collisions are compared to
published observations of current sheets in the Earth's magnetosheath and the
solar wind, and the nature of these current sheets leads to the expectation
that Landau damping of the constituent Alfven waves plays a dominant role in
the damping of turbulently generated current sheets.
