The charge density wave instability in one-dimensional semimetals is usually explained through a Peierls-like mechanism, where the coupling of electrons and phonons induces a periodic lattice distortion along certain modes of vibration, leading to a gap opening in the electronic band structure and to a lowering of the symmetry of the lattice. In this work, we study two prototypical Peierls systems: the one-dimensional carbon chain and the monatomic hydrogen chain with accurate ab initio calculations based on quantum Monte Carlo and hybrid density functional theory. We demonstrate that in one-dimensional semimetals at T=0, a purely electronic instability can exist independently of a lattice distortion. It is induced by spontaneous formation of low energy electron-hole pairs resulting in the electronic band gap opening, i.e., the destabilization of the semimetallic phase is due to an excitonic mechanism.

Excitonic-insulator instability and Peierls distortion in one-dimensional semimetals / Barborini, M.; Calandra Buonaura, M.; Mauri, F.; Wirtz, L.; Cudazzo, P.. - In: PHYSICAL REVIEW. B. - ISSN 2469-9950. - 105:7(2022). [10.1103/PhysRevB.105.075122]

Excitonic-insulator instability and Peierls distortion in one-dimensional semimetals

Calandra Buonaura M.;Cudazzo P.
2022-01-01

Abstract

The charge density wave instability in one-dimensional semimetals is usually explained through a Peierls-like mechanism, where the coupling of electrons and phonons induces a periodic lattice distortion along certain modes of vibration, leading to a gap opening in the electronic band structure and to a lowering of the symmetry of the lattice. In this work, we study two prototypical Peierls systems: the one-dimensional carbon chain and the monatomic hydrogen chain with accurate ab initio calculations based on quantum Monte Carlo and hybrid density functional theory. We demonstrate that in one-dimensional semimetals at T=0, a purely electronic instability can exist independently of a lattice distortion. It is induced by spontaneous formation of low energy electron-hole pairs resulting in the electronic band gap opening, i.e., the destabilization of the semimetallic phase is due to an excitonic mechanism.
2022
7
Barborini, M.; Calandra Buonaura, M.; Mauri, F.; Wirtz, L.; Cudazzo, P.
Excitonic-insulator instability and Peierls distortion in one-dimensional semimetals / Barborini, M.; Calandra Buonaura, M.; Mauri, F.; Wirtz, L.; Cudazzo, P.. - In: PHYSICAL REVIEW. B. - ISSN 2469-9950. - 105:7(2022). [10.1103/PhysRevB.105.075122]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11572/336036
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