Efficient simulation of moire materials using the density matrix renormalization group
| Autor: | Nick Bultinck, Johannes Hauschild, Michael P. Zaletel, Daniel E. Parker, Tomohiro Soejima |
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| Rok vydání: | 2020 |
| Předmět: |
CASCADE
Fluids & Plasmas Degrees of freedom (statistics) FOS: Physical sciences TRANSITIONS 02 engineering and technology Space (mathematics) 01 natural sciences MAGIC-ANGLE Condensed Matter - Strongly Correlated Electrons Engineering Quantum mechanics 0103 physical sciences Coulomb 010306 general physics Physics Strongly Correlated Electrons (cond-mat.str-el) SUPERCONDUCTIVITY Density matrix renormalization group Operator (physics) Renormalization group 021001 nanoscience & nanotechnology Physics and Astronomy ELECTRIC POLARIZATION Physical Sciences Chemical Sciences Condensed Matter::Strongly Correlated Electrons cond-mat.str-el 0210 nano-technology Bilayer graphene Ground state |
| Zdroj: | PHYSICAL REVIEW B Physical Review B, vol 102, iss 20 |
| ISSN: | 2469-9950 2469-9969 |
| DOI: | 10.48550/arxiv.2009.02354 |
| Popis: | We present an infinite density-matrix renormalization group (DMRG) study of an interacting continuum model of twisted bilayer graphene (tBLG) near the magic angle. Because of the long-range Coulomb interaction and the large number of orbital degrees of freedom, tBLG is difficult to study with standard DMRG techniques -- even constructing and storing the Hamiltonian already poses a major challenge. To overcome these difficulties, we use a recently developed compression procedure to obtain a matrix product operator representation of the interacting tBLG Hamiltonian which we show is both efficient and accurate even when including the spin, valley and orbital degrees of freedom. To benchmark our approach, we focus mainly on the spinless, single-valley version of the problem where, at half-filling, we find that the ground state is a nematic semimetal. Remarkably, we find that the ground state is essentially a k-space Slater determinant, so that Hartree-Fock and DMRG give virtually identical results for this problem. Our results show that the effects of long-range interactions in magic angle graphene can be efficiently simulated with DMRG, and opens up a new route for numerically studying strong correlation physics in spinful, two-valley tBLG, and other moire materials, in future work. Comment: corrected a typo in arxiv author list |
| Databáze: | OpenAIRE |
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