Mott insulators ─ exotica inside crystals
Mott insulators exhibit a drastic electron system change associated with the insulator-metal transition. Near what is known as the Mott transition, extraordinary phenomena like high-temperature superconductivity and colossal magnetoresistance arise from the interplay among charge and spin. While these unexpected effects should form the basis of future oxide electronics, the mechanisms underlying these phenomena are still under debate. The MOTTPROXIMITY (Electronic properties in the vicinity of a Mott insulator) project was launched to look into mechanisms by which their insulating behaviour is destroyed. With the financial support of the EU, the project team developed numerical and analytical techniques to gain a better understanding of electronic and atomic systems near the Mott transition. Quantum Monte Carlo algorithms were used to map superconducting fluctuations in materials such as superconducting cuprates. The parent compound of these materials is an antiferromagnetic Mott insulator that becomes a superconductor upon doping. Scientists investigated the effects of inhomogeneities at the nanostructure level on their bulk electronic properties as well as the superconducting temperature. Research on the Higgs mode has also led to a number of interesting results including the universal properties of Higgs excitations near the Mott transition phase. Some of the theoretical results have been confirmed by experiments performed on rubidium gas in an optical lattice. To disseminate these findings, the scientists have published eight papers in renowned peer-reviewed journals. The MOTTPROXIMITY project results are expected to have an important impact on research carried out on condensed matter and cold atomic gases.
Keywords
Mott insulator, metal-insulator transition, superconductivity, quantum Monte Carlo, cold atomic gases
