Charge-Density-Wave Quantum Materials and Devices

The charge-density-wave (CDW) phase is a macroscopic quantum state consisting of a periodic modulation of the electronic charge density accompanied by a periodic distortion of the atomic lattice. Unconventional forms of superconductivity frequently emerge from a CDW phase hence the fundamental interest. The early work on CDW effects was performed with bulk samples, which have quasi-one-dimensional (1D) crystal structures of strongly-bound 1D atomic chains that are weakly bound together by van-der-Waals forces. Many spectacular observations were made – nonlinear transport, oscillating electric current for time independent voltages, effects analogous to the Josephson effect observed in superconductors, giant dielectric response, by-stable conducting states, just to mention a few. Recent years witnessed a rebirth of the CDW field found in layered quasi-two-dimensional (2D) van der Waals materials and, in some cases CDW manifestation at room temperature (RT) and above. The interest to quasi-1D CDW materials has also reemerged due to recent finding of topological nontriviality of many of them. Despite numerous open physics questions, the CDW quantum materials field is rapidly evolving towards applied physics and engineering domains with application potential for amplifiers, detectors, memory, optoelectronic devices, information processing and radiation-hard electronics.