  Intermittency refers to the broken self-similarity of turbulent flows caused
by anomalous spatio-temporal fluctuations. In this Letter, we ask how
intermittency is affected by a non-dissipative viscosity, known as odd
viscosity (also Hall or gyro-viscosity), which appears in parity-breaking
fluids such as magnetized polyatomic gases, electron fluids under magnetic
field and spinning colloids or grains. Using a combination of Navier-Stokes
simulations and theory, we show that intermittency is suppressed by odd
viscosity at small scales. This effect is caused by parity-breaking waves,
induced by odd viscosity, that break the multiple scale invariances of the
Navier-Stokes equations. Building on this insight, we construct a two-channel
helical shell model that reproduces the basic phenomenology of turbulent
odd-viscous fluids including the suppression of anomalous scaling. Our findings
illustrate how a fully developed direct cascade that is entirely self-similar
can emerge below a tunable length scale, paving the way for designing turbulent
flows with adjustable levels of intermittency.
