Superlattice

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A superlattice is a material with periodically alternating layers of several substances. Such structures possess periodicity both on the scale of each layer's crystal lattice and on the scale of the alternating layers. This leads to characteristic satellite peaks in X-ray diffraction patterns. Depending on the nature of components, a superlattice may be called magnetic, optical or semiconductor.

The motion of charge carriers in a superlattice is modified with respect to each individual lattice. This can lead to significant increase of carrier mobility (used in microwave devices) or special optical features (such as a semiconductor laser).

There also exists a class of quasiperiodic superlattices named after Fibonacci. The Fibonacci superlattices are usually studied as a single-dimensional model of quasicrystal, where either electron hopping transfer interactions or on-site energies take two values arranged in a Fibonacci sequence.

[edit] References

• Ivan K. Schuller, "A New Class of Layered Materials", Phys. Rev. Lett. 44, 1597 (1980).