Nanoscale Quantum Physics Group

Research - Project Two

The Princess and the Pea: Imaging buried interfacial lattices with quantized electrons

We demonstrate that the well-known Si(111)-(7 X 7) superlattice buried under as much as 100 Å of crystalline Pb can be directly imaged with a scanning tunneling microscope at 77 K. The unexpected transparency of the metal and the high lateral resolution are the result of a nondiffractive scattering of the electrons at the interface. We attribute this phenomenon to a large anisotropy of the effective masses associated with the free in-plane and the quantized transverse motion of the electrons.

For a detailed description see Altfeder, I.B., Chen, D.M., Matveev, K.A. “Imaging Buried Interfacial Lattices with Quantized Electrons”, Phys. Rev. Lett., 80, 4895-4898 (1998).

See also “Dowsing for Silicon”, in Physical Review Focus 1, story 17, (1998) and Science News, 153, 358 (1998).