Toward a predictive theory of correlated materials

Abstract

Correlated electron materials display a rich variety of notable properties ranging from unconventional superconductivity to metal-insulator transitions. These properties are of interest from the point of view of applications but are hard to treat theoretically, as they result from multiple competing energy scales. Although possible in more weakly correlated materials, theoretical design and spectroscopy of strongly correlated electron materials have been a difficult challenge for many years. By treating all the relevant energy scales with sufficient accuracy, complementary advances in Green's functions and quantum Monte Carlo methods open a path to first-principles computational property predictions in this class of materials.

Origins of the odd optical observables in plutonium and americium tungstates

“…Rather than continuing to speculate on the origins of the unusual colors exhibited in these systems—and their possible connection with 5f-electron covalency,—here we calculate the electronic structure of PuW 2 O 7 and AmWO 4 employing the local density approximation (LDA)57 to density functional theory (DFT)58,59 in combination with dynamical mean field theory (LDA + DMFT)60–62 and in combination with the Gutzwiller approximation (LDA + GA),63–67 which are techniques specifically designed to capture the electron correlations beyond the single-particle picture underlining classic approximations to DFT 68–70…”

Solving the strong-correlation problem in materials

“…The third is the (so-far increasing) power of massively parallel supercomputers, which made actual calculations possible in practice. All this gave birth to the DFT+DMFT approach [41,75,101,107,[109][110][111][112][113], described in a schematic way in Fig. 8.…”

“…A representative, although not exhaustive, list of success stories can be found, e.g., in Refs. [41,101,107,[110][111][112][113]. As an example we show in Fig.…”

Applications of DFT + DMFT in Materials Science

“…This approach takes into account the nonsphericity of the impurity, and has so far produced good agreement with the experiment (36,47), possibly concluding the discussion over the different DC approaches. Another area where there is need for new developments is the numerical impurity solvers, which solve the AIM to calculate the self energy Σ(ω) from the hybridization ∆(ω) (8). The state of the art is the continuous time quantum Monte Carlo methods introduced for this purpose (48,49,50) which are in principle exact, and efficiently parallelizable over a large number of processors.…”