Electron-electron interactions, topological phase, and optical properties of a charged artificial benzene ring

Özfidan, Işıl; Vladisavljevic, Milos; Korkusiński, Marek; Hawrylak, Paweł

doi:10.1103/physrevb.92.245304

Cited by 5 publications

(3 citation statements)

References 65 publications

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“…Donor positions are assigned at evenly spaced (R 0 ) substitutional atomic sites in Si along a [110] crystalline direction. The many-body state is described within the Configuration Interaction (CI) framework [17][18][19][20] and diagonalized exactly. Since Si is a material with very low spin-orbit coupling and no piezoelectric phonons, it is reasonable to assume that spin relaxation times are much longer than all other time scales involved in the experiment, so that thermalization does not remove the system from the S z = 0 subspace.…”

Section: Resultsmentioning

confidence: 99%

Adequacy of Si:P chains as Fermi–Hubbard simulators

et al. 2018

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The challenge of simulating many-body models with analogue physical systems requires both experimental precision and very low operational temperatures. Atomically precise placement of dopants in Si permits the construction of nanowires by design. We investigate the suitability of these interacting electron systems as simulators of a fermionic extended Hubbard model on demand. We describe the single-particle wavefunctions as a linear combination of dopant orbitals (LCDO). The electronic states are calculated within configuration interaction (CI). Due to the peculiar oscillatory behavior of each basis orbital, properties of these chains are strongly affected by the interdonor distance R 0 , in a non-monotonic way. Ground state (T = 0 K) properties such as charge and spin correlations are shown to remain robust under temperatures up to 4 K for specific values of R 0 . The robustness of the model against disorder is also tested, allowing some fluctuation of the placement site around the target position. We suggest that finite donor chains in Si may serve as an analog simulator for strongly correlated model Hamiltonians. This simulator is, in many ways, complementary to those based on cold atoms in optical lattices-the trade-off between the tunability achievable in the latter and the survival of correlation at higher operation temperatures for the former suggests that both technologies are applicable for different regimes.

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Section: Resultsmentioning

confidence: 99%

Adequacy of Si:P chains as Fermi–Hubbard simulators

et al. 2018

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“…By contrast, edge states in topologically nontrivial insulators are robust and give rise to novel physics. For example, one can envisage edge states as realizations of one-dimensional (1D) strongly interacting systems and, as will be discussed in this paper, sites in one-dimensional Hubbard models [ 28 , 29 ]. Edge states also arise naturally in the study of quantum dots in two-dimensional (2D) materials such as graphene [ 16 ].…”

Section: Introductionmentioning

confidence: 99%

Edge States and Strain-Driven Topological Phase Transitions in Quantum Dots in Topological Insulators

et al. 2022

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We present here a theory of the electronic properties of quasi two-dimensional quantum dots made of topological insulators. The topological insulator is described by either eight band k→·p→ Hamiltonian or by a four-band k→·p→ Bernevig–Hughes–Zhang (BHZ) Hamiltonian. The trivial versus topological properties of the BHZ Hamiltonian are characterized by the different topologies that arise when mapping the in-plane wavevectors through the BHZ Hamiltonian onto a Bloch sphere. In the topologically nontrivial case, edge states are formed in the disc and square geometries of the quantum dot. We account for the effects of compressive strain in topological insulator quantum dots by means of the Bir–Pikus Hamiltonian. Tuning strain allows topological phase transitions between topological and trivial phases, which results in the vanishing of edge states from the energy gap. This may enable the design of a quantum strain sensor based on strain-driven transitions in HgTe topological insulator square quantum dots.

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“…For all other degenerate states, away from half-filling, the Hund rule is discussed in the text. [48,49], or in discretized quantum rings [22]. It was also found to be a good approximation to describe the electronic dynamics in planar models of circular molecules as cyclobutadiene [35] or cyclooctatetraene [50,51] when the Hükel model is used.…”

Section: Circular Molecule and The Interacting Potentialmentioning

confidence: 99%

Hund and anti-Hund rules in circular molecules

et al. 2017

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We study the validity of Hund's first rule for the spin multiplicity in circular molecules -made of real or artificial atoms such as quantum dots -by considering a perturbative approach in the Coulomb interaction in the extended Hubbard model with both on-site and long-range interactions. In this approximation, we show that an anti-Hund rule always defines the ground state in a molecule with 4N atoms at half-filling. In all other cases (i.e. number of atoms not multiple of four, or a 4N molecule away from half-filling) both the singlet and the triplet outcomes are possible, as determined primarily by the total number of electrons in the system. In some instances, the Hund rule is always obeyed and the triplet ground state is realized mathematically for any values of the on-site and long range interactions, while for other filling situations the singlet is also possible but only if the long-range interactions exceed a certain threshold, relatively to the on-site interaction.

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Electron-electron interactions, topological phase, and optical properties of a charged artificial benzene ring

Cited by 5 publications

References 65 publications

Adequacy of Si:P chains as Fermi–Hubbard simulators

Adequacy of Si:P chains as Fermi–Hubbard simulators

Edge States and Strain-Driven Topological Phase Transitions in Quantum Dots in Topological Insulators

Hund and anti-Hund rules in circular molecules

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