Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2601.12487 · Physical review. B./Physical review. B

Influence of leads on signatures of strongly correlated zero-bias anomaly in double quantum dot measurements

Caden Drover, R. L. Irvine, Rachel Wortis

Published Jan 14, 2026• 0 citations
arXivHTMLPDF

Abstract

The combination of disorder and interactions is known in many systems to produce a feature in the single-particle density of states, the shape and parameter dependence of which act as signatures of the underlying electronic state. Strong Coulomb repulsion gives rise to a host of novel phenomena, among these is a unique zero-bias anomaly. While understanding of the anomaly in bulk materials remains incomplete, a version of this anomaly can be found in an ensemble of two-site systems and hence has been predicted to be observable in parallel-coupled double quantum dots. However, prior work did not include the influence of the leads. Here we show that the presence of the leads results in changes to the projected stability diagrams but that the signature of the strongly-correlated zero-bias anomaly nonetheless remains clearly visible.

DOI
10.1103/6tyd-f26y

Related papers

Strongly correlated zero-bias anomaly in double quantum dot measurements

Rachel Wortis, Joshua Folk, Silvia Lüscher +1 more

Experiments in doped transition metal oxides often show suppression in the single-particle density of states at the Fermi level, but disorder-induced zero-bias anomalies in strongly correlated systems remain poorly understood. Numerical studies of the Anderson-Hubbard model have identified a zero-bias anomaly that is unique to strongly correlated materials, with a width proportional to the intersite hopping amplitude $t$ [S. Chiesa, P. B. Chakraborty, W. E. Pickett, and R. T. Scalettar, Phys. Rev. Lett. 101, 086401 (2008)]. In ensembles of two-site systems, a zero-bias anomaly with the same parameter dependence also occurs, suggesting a similar physical origin R. Wortis and W. A. Atkinson, Phys. Rev. B 82, 073107 (2010)]. We describe how this kinetic-energy-driven zero-bias anomaly in ensembles of two-site systems may be seen in a mesoscopic realization based on double quantum dots. Moreover, the double-quantum-dot measurements provide access not only to the ensemble-average density of states but also to the details of the transitions which give rise to the zero-bias anomaly.

arXiv:2109.13782•Physical review. B./Physical review. B•Jun 13, 2022•0 citations

Effect of nonlocal interactions on the disorder-induced zero-bias anomaly in the Anderson-Hubbard model

Hong-Yi Chen, W. A. Atkinson, Rachel Wortis

To expand the framework available for interpreting experiments on disordered strongly correlated systems, and in particular to explore further the strong-coupling zero-bias anomaly found in the Anderson-Hubbard model, we ask how this anomaly responds to the addition of nonlocal electron-electron interactions. We use exact diagonalization to calculate the single-particle density of states of the extended Anderson-Hubbard model. We find that for weak nonlocal interactions the form of the zero-bias anomaly is qualitatively unchanged. The energy scale of the anomaly continues to be set by an effective hopping amplitude renormalized by the nonlocal interaction. At larger values of the nonlocal interaction strength, however, hopping ceases to be a relevant energy scale and higher energy features associated with charge correlations dominate the density of states.

arXiv:1203.5366•Physical Review B•Jun 21, 2012•4 citations

Effect of strong correlations on the disorder-induced zero bias anomaly in the two-site Anderson-Hubbard model

Hong-Yi Chen, W. A. Atkinson

Several recent exact-diagonalization calculations have established that the Anderson-Hubbard model has a disorder-induced zero bias anomaly (ZBA) (also called a disorder-induced pseudogap) in the density of states. In order to understand the physics of the ZBA, we study a simplified problem---an ensemble of two-site molecules with random site energies---for which analytical results are possible. For this ensemble, we examine how the ZBA forms in both the weakly correlated (mean field) and strongly correlated limits. In the weakly correlated case, the ZBA can be understood as the result of level repulsion between bonding and antibonding molecular orbitals. A similar level repulsion occurs in the strongly correlated case too but a larger contribution to the ZBA comes from the suppression of a triplet excitation mode. This inherently many-body mechanism does not have a counterpart in mean-field models.

arXiv:1006.2401•Physical Review B•Sep 9, 2010•8 citations

Zero bias anomaly in the two-site Anderson-Hubbard model with Gaussian distribution for disorder

Oanh Thi Kim Nguyen, Nam Van Tran, Giang H. Bach

Abstract The Anderson-Hubbard model considers the correlation between disorder and other interactions in a strongly correlated electron system. Both disorder and correlations drive the metal-insulator transition but the densities of states behave in different ways. The zero bias anomaly (ZBA) referring to the V-dip shape of the density of states at the Fermi energy occurs in the strong disorder and strong interaction regime instead of a hard Coulomb gap in an insulator phase of strongly correlated interacting systems. In this paper, we use a Gaussian distribution for disorder to examine a two-site Anderson-Hubbard model. We also explain comprehensively the relationship between the phase diagram of ground states with various numbers of electrons and the behavior of the density of states. Furthermore, we want to investigate the effect of disorder distribution on the formation of the ZBA which originates from a hopping mechanism in two specific configurations.

Journal of Physics Conference Series•Jul 1, 2019•0 citations

Physical mechanism for a kinetic energy driven zero-bias anomaly in the Anderson-Hubbard model

Rachel Wortis, W. A. Atkinson

The combined effects of strong disorder, strong correlations, and hopping in the Anderson-Hubbard model have been shown to produce a zero-bias anomaly which has an energy scale proportional to the hopping and minimal dependence on interaction strength, disorder strength, and doping. Disorder-induced suppression of the density of states for a purely local interaction is inconsistent with both the Efros-Shklovskii Coulomb gap and the Altshuler-Aronov anomaly, and moreover the energy scale of this anomaly is inconsistent with the standard energy scales of both weak- and strong-coupling pictures. We demonstrate that a density of states anomaly with similar features arises in an ensemble of two-site systems, and we argue that the energy scale $t$ emerges in strongly correlated systems with disorder due to the mixing of lower and upper Hubbard orbitals on neighboring sites.

arXiv:1004.3309•Physical Review B•Aug 31, 2010•13 citations

Temperature dependence of the zero-bias anomaly in the Anderson–Hubbard model: insights from an ensemble of two-site systems

Rachel Wortis, W. A. Atkinson

Motivated by experiments on doped transition metal oxides, this paper considers the interplay of interactions, disorder, kinetic energy and temperature in a simple system. An ensemble of two-site Anderson-Hubbard model systems has already been shown to display a zero-bias anomaly (Wortis and Atkinson 2010 Phys. Rev. B 82 073107) which shares features with that found in the two-dimensional Anderson-Hubbard model (Chiesa et al 2008 Phys. Rev. Lett. 101 086401). Here the temperature dependence of the density of states of this ensemble is examined. In the atomic limit, there is no zero-bias anomaly at zero temperature, but one develops at small nonzero temperatures. With hopping, small temperatures augment the zero-temperature kinetic-energy-driven zero-bias anomaly, while at larger temperatures the anomaly is filled in.

arXiv:1008.2245•Journal of Physics Condensed Matter•Feb 17, 2011•6 citations
The combination of disorder and interactions is known in many systems to produce a feature in the single-particle density of states, the shape and parameter dependence of which act as signatures of the underlying electronic state. Strong Coulomb repulsion gives rise to a host of novel phenomena, among these is a unique zero-bias anomaly. While understanding of the anomaly in bulk materials remains incomplete, a version of this anomaly can be found in an ensemble of two-site systems and hence has been predicted to be observable in parallel-coupled double quantum dots. However, prior work did not include the influence of the leads. Here we show that the presence of the leads results in changes to the projected stability diagrams but that the signature of the strongly-correlated zero-bias anomaly nonetheless remains clearly visible.
Experiments in doped transition metal oxides often show suppression in the single-particle density of states at the Fermi level, but disorder-induced zero-bias anomalies in strongly correlated systems remain poorly understood. Numerical studies of the Anderson-Hubbard model have identified a zero-bias anomaly that is unique to strongly correlated materials, with a width proportional to the intersite hopping amplitude ttt [S. Chiesa, P. B. Chakraborty, W. E. Pickett, and R. T. Scalettar, Phys. Rev. Lett. 101, 086401 (2008)]. In ensembles of two-site systems, a zero-bias anomaly with the same parameter dependence also occurs, suggesting a similar physical origin R. Wortis and W. A. Atkinson, Phys. Rev. B 82, 073107 (2010)]. We describe how this kinetic-energy-driven zero-bias anomaly in ensembles of two-site systems may be seen in a mesoscopic realization based on double quantum dots. Moreover, the double-quantum-dot measurements provide access not only to the ensemble-average density of states but also to the details of the transitions which give rise to the zero-bias anomaly.
To expand the framework available for interpreting experiments on disordered strongly correlated systems, and in particular to explore further the strong-coupling zero-bias anomaly found in the Anderson-Hubbard model, we ask how this anomaly responds to the addition of nonlocal electron-electron interactions. We use exact diagonalization to calculate the single-particle density of states of the extended Anderson-Hubbard model. We find that for weak nonlocal interactions the form of the zero-bias anomaly is qualitatively unchanged. The energy scale of the anomaly continues to be set by an effective hopping amplitude renormalized by the nonlocal interaction. At larger values of the nonlocal interaction strength, however, hopping ceases to be a relevant energy scale and higher energy features associated with charge correlations dominate the density of states.
Several recent exact-diagonalization calculations have established that the Anderson-Hubbard model has a disorder-induced zero bias anomaly (ZBA) (also called a disorder-induced pseudogap) in the density of states. In order to understand the physics of the ZBA, we study a simplified problem---an ensemble of two-site molecules with random site energies---for which analytical results are possible. For this ensemble, we examine how the ZBA forms in both the weakly correlated (mean field) and strongly correlated limits. In the weakly correlated case, the ZBA can be understood as the result of level repulsion between bonding and antibonding molecular orbitals. A similar level repulsion occurs in the strongly correlated case too but a larger contribution to the ZBA comes from the suppression of a triplet excitation mode. This inherently many-body mechanism does not have a counterpart in mean-field models.
Abstract The Anderson-Hubbard model considers the correlation between disorder and other interactions in a strongly correlated electron system. Both disorder and correlations drive the metal-insulator transition but the densities of states behave in different ways. The zero bias anomaly (ZBA) referring to the V-dip shape of the density of states at the Fermi energy occurs in the strong disorder and strong interaction regime instead of a hard Coulomb gap in an insulator phase of strongly correlated interacting systems. In this paper, we use a Gaussian distribution for disorder to examine a two-site Anderson-Hubbard model. We also explain comprehensively the relationship between the phase diagram of ground states with various numbers of electrons and the behavior of the density of states. Furthermore, we want to investigate the effect of disorder distribution on the formation of the ZBA which originates from a hopping mechanism in two specific configurations.
The combined effects of strong disorder, strong correlations, and hopping in the Anderson-Hubbard model have been shown to produce a zero-bias anomaly which has an energy scale proportional to the hopping and minimal dependence on interaction strength, disorder strength, and doping. Disorder-induced suppression of the density of states for a purely local interaction is inconsistent with both the Efros-Shklovskii Coulomb gap and the Altshuler-Aronov anomaly, and moreover the energy scale of this anomaly is inconsistent with the standard energy scales of both weak- and strong-coupling pictures. We demonstrate that a density of states anomaly with similar features arises in an ensemble of two-site systems, and we argue that the energy scale ttt emerges in strongly correlated systems with disorder due to the mixing of lower and upper Hubbard orbitals on neighboring sites.
Motivated by experiments on doped transition metal oxides, this paper considers the interplay of interactions, disorder, kinetic energy and temperature in a simple system. An ensemble of two-site Anderson-Hubbard model systems has already been shown to display a zero-bias anomaly (Wortis and Atkinson 2010 Phys. Rev. B 82 073107) which shares features with that found in the two-dimensional Anderson-Hubbard model (Chiesa et al 2008 Phys. Rev. Lett. 101 086401). Here the temperature dependence of the density of states of this ensemble is examined. In the atomic limit, there is no zero-bias anomaly at zero temperature, but one develops at small nonzero temperatures. With hopping, small temperatures augment the zero-temperature kinetic-energy-driven zero-bias anomaly, while at larger temperatures the anomaly is filled in.