  We demonstrate that a system of nonlocally coupled noisy phase oscillators
can collectively exhibit a hole structure, which manifests itself in the
spatial phase distribution of the oscillators. The phase model is described by
a nonlinear Fokker-Planck equation, which can be reduced to the complex
Ginzburg-Landau equation near the Hopf bifurcation point of the uniform
solution. By numerical simulations, we show that the hole structure clearly
appears in the space-dependent order parameter, which corresponds to the
Nozaki-Bekki hole solution of the complex Ginzburg-Landau equation.
