An organizing principle for two-dimensional strongly correlated superconductivity

AbstractWith a combination of numerical methods, including quantum Monte Carlo, exact diagonalization, and a simplified dynamical mean-field model, we consider the attosecond charge dynamics of electrons induced by strong-field laser pulses in two-dimensional Mott insulators. The necessity to go beyond single-particle approaches in these strongly correlated systems has made the simulation of two-dimensional extended materials challenging, and we contrast their resulting high-harmonic emission with more widely studied one-dimensional analogues. As well as considering the photo-induced breakdown of the Mott insulating state and magnetic order, we also resolve the time and ultra-high-frequency domains of emission, which are used to characterize both the photo-transition, and the sub-cycle structure of the electron dynamics. This extends simulation capabilities and understanding of the photo-melting of these Mott insulators in two dimensions, at the frontier of attosecond non-equilibrium science of correlated materials.

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Metal-to-Insulator Transitions in Strongly Correlated Regime

Applied Sciences ◽

10.3390/app9010080 ◽

2018 ◽

Vol 9 (1) ◽

pp. 80

Author(s):

Jian Huang ◽

Loren Pfeiffer ◽

Ken West

Keyword(s):

Critical Behavior ◽

Intermediate Phase ◽

Insulator Transition ◽

Order Transition ◽

Strongly Correlated ◽

Two Dimensional ◽

First Order ◽

Wigner Crystallization ◽

Metal To Insulator Transition ◽

First Order Transition

Transport results from measuring ultra-clean two-dimensional systems, containing tunable carrier densities from 7 × 10 8 cm − 2 to ∼ 1 × 10 10 cm − 2 , reveal a strongly correlated liquid up to r s ≈ 40 where a Wigner crystallization is anticipated. A critical behavior is identified in the proximity of the metal-to-insulator transition. The nonlinear DC responses for r s > 40 captures hard pinning modes that likely undergo a first order transition into an intermediate phase in the course of melting.

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Artificial two-dimensional polar metal by charge transfer to a ferroelectric insulator

Communications Physics ◽

10.1038/s42005-019-0227-4 ◽

2019 ◽

Vol 2 (1) ◽

Cited By ~ 8

Author(s):

W. X. Zhou ◽

H. J. Wu ◽

J. Zhou ◽

S. W. Zeng ◽

C. J. Li ◽

...

Keyword(s):

Carrier Density ◽

Room Temperature ◽

Electronic Devices ◽

General Concept ◽

Polar Phase ◽

Strongly Correlated ◽

Two Dimensional ◽

Single System ◽

Oxide Interfaces ◽

Mobile Carrier

Abstract Integrating multiple properties in a single system is crucial for the continuous developments in electronic devices. However, some physical properties are mutually exclusive in nature. Here, we report the coexistence of two seemingly mutually exclusive properties-polarity and two-dimensional conductivity-in ferroelectric Ba0.2Sr0.8TiO3 thin films at the LaAlO3/Ba0.2Sr0.8TiO3 interface at room temperature. The polarity of a ∼3.2 nm Ba0.2Sr0.8TiO3 thin film is preserved with a two-dimensional mobile carrier density of ∼0.05 electron per unit cell. We show that the electronic reconstruction resulting from the competition between the built-in electric field of LaAlO3 and the polarization of Ba0.2Sr0.8TiO3 is responsible for this unusual two-dimensional conducting polar phase. The general concept of exploiting mutually exclusive properties at oxide interfaces via electronic reconstruction may be applicable to other strongly-correlated oxide interfaces, thus opening windows to new functional nanoscale materials for applications in novel nanoelectronics.

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Photoexcited states of two-dimensional strongly correlated electron systems

Physical Review B ◽

10.1103/physrevb.65.085103 ◽

2002 ◽

Vol 65 (8) ◽

Cited By ~ 10

Author(s):

Akira Takahashi ◽

Sadakazu Yoshikawa ◽

Masaki Aihara

Keyword(s):

Strongly Correlated Electron Systems ◽

Strongly Correlated ◽

Two Dimensional ◽

Electron Systems ◽

Strongly Correlated Electron ◽

Correlated Electron Systems ◽

Correlated Electron

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Condensation to a strongly correlated dark fluid of two dimensional dipolar excitons

Superlattices and Microstructures ◽

10.1016/j.spmi.2017.01.022 ◽

2017 ◽

Vol 108 ◽

pp. 88-97 ◽

Cited By ~ 2

Author(s):

Yotam Mazuz-Harpaz ◽

Kobi Cohen ◽

Ronen Rapaport

Keyword(s):

Strongly Correlated ◽

Two Dimensional ◽

Dark Fluid

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An ideal Josephson junction in an ultracold two-dimensional Fermi gas

Science ◽

10.1126/science.aaz2342 ◽

2020 ◽

Vol 369 (6499) ◽

pp. 89-91 ◽

Cited By ~ 7

Author(s):

Niclas Luick ◽

Lennart Sobirey ◽

Markus Bohlen ◽

Vijay Pal Singh ◽

Ludwig Mathey ◽

...

Keyword(s):

Josephson Junction ◽

High Temperature Superconductors ◽

Fermi Gas ◽

Current Phase ◽

Strongly Correlated ◽

Two Dimensional ◽

Weakly Bound ◽

Ideal Model System ◽

Sinusoidal Current ◽

2D Fermi Gas

The role of reduced dimensionality in high-temperature superconductors is still under debate. Recently, ultracold atoms have emerged as an ideal model system to study such strongly correlated two-dimensional (2D) systems. Here, we report on the realization of a Josephson junction in an ultracold 2D Fermi gas. We measure the frequency of Josephson oscillations as a function of the phase difference across the junction and find excellent agreement with the sinusoidal current phase relation of an ideal Josephson junction. Furthermore, we determine the critical current of our junction in the crossover from tightly bound molecules to weakly bound Cooper pairs. Our measurements clearly demonstrate phase coherence and provide strong evidence for superfluidity in a strongly interacting 2D Fermi gas.

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