Effect of magnetic field on the noise behavior of disordered conductors

Shot noise suppression induced by magnetic field has been a topic of intense scientific debate in the last two decades, in particular with reference to the so-called chaotic or mesoscopic cavities, where the formation of edge states leads to a suppression of scattering and therefore of diffraction at the apertures, as well as of noise. By means of numerical simulations based on a recursive Green's function technique we study the effect of an orthogonal magnetic field on transport and noise through different disordered conductors. The magnetic field is included into the calculation by means of a Peierls phase factor. Confirming Büttiker's conjecture, we find that noiseless edge states are formed when the cyclotron diameter becomes smaller than the average separation between scatterers, so that transmission becomes a multiple of the conductance quantum and noise drops to zero. Overall, as the magnetic field value rises, shot noise is increasingly suppressed, as a consequence of transmission eigenvalues getting close to unity.