  Dual-phase time projection chambers (TPCs) filled with the liquid noble gas
xenon (LXe) are currently the most sensitive detectors searching for
interactions of WIMP dark matter in a laboratory-based experiment. This is
achieved by combining a large, monolithic dark matter target of a very low
background with the capability to localize the interaction vertex in three
dimensions, allowing for target fiducialization and multiple-scatter rejection.
The background in dual-phase LXe TPCs is further reduced by the simultaneous
measurement of the scintillation and ionization signal from a particle
interaction, which is used to distinguish signal from background signatures.
This article reviews the principle of dual-phase LXe TPCs, and provides an
overview about running as well as future experimental efforts.
