Magnetic field induced linear Coulomb gap in tunnelling between disordered two-dimensional electron systems

We have investigated equilibrium tunnelling between disordered two-dimensional electron systems at temperatures below View the MathML source over a wide range of magnetic field, B, applied perpendicular to the electron layers. In zero field, we observe a narrow conductance peak of about View the MathML source width at zero bias. As B is increased, this is transformed into a narrow linear gap in the tunnel spectrum. The existence of the linear gap is discussed in terms of many-electron interaction effects.