  Charge-density-wave (CDW) is a modulation of the conduction electron density
in a conductor. Under low temperature, it can spontaneously happen in some
compounds that consist of anisotropic one-dimensional crystal structures, via a
strong electron-lattice interaction mechanism. Many celebrated phenomena, e.g.
non-linear transport, narrow-band noise, mode-locking5 and chaos under AC
voltage, etc., have been reported in CDW. However, evaluating the application
potential of CDW conductors has been hampered by the inconvenient shapes and
sizes of CDW single crystals. Although modern fabrication technology can partly
resolve those troubles, (for example, cleaved film and nanowire NbSe3 device),
the imperfections induced by fabrication that corrupt measured properties are
not easy to control and estimate. Here we demonstrate a convenient CDW
conductor fabricated by semiconductor double quantum wells (DQW) in a
field-effect transistor (FET) configuration: a modulated electron density in
one QW resulted from the charged QW nearby. The electric field dependent
depinning transport characteristic of CDW is clearly present. This "artificial"
CDW, capable of integrating with semiconductor industry, may give fresh impetus
to revive the interests in CDW.
