Direct observation of standing electron waves in diffusively conducting InAs nanowire

We investigate the disturbance of the InAs nanowire resistance by a conductive tip of a scanning probe microscope at helium temperature as a function of the tip position in close vicinity to the nanowire. At the tip displacement along the wire the resistance ($R_{\rm wire} \simeq 30$ k$\Omega$, what is typical for diffusive regime) demonstrates quasi-periodical oscillations with an amplitude about $3\%$. The period of the oscillations depends on the number of electrons in the nanowire and is consistent with expected for standing electron waves caused by ballistic electrons in the top subband of the InAs nanowire.