408 research outputs found
Evidence of weak superconductivity at the room-temperature grown LaAlO<sub>3</sub>/SrTiO<sub>3</sub> interface
The two-dimensional electron gas at the crystalline LaAlO3/SrTiO3 (c-LAO/STO) interface has sparked large interest due to its exotic properties, including an intriguing gate-tunable superconducting phase. While there is growing evidence of pronounced spatial inhomogeneity in the conductivity at STO-based interfaces, the consequences for superconductivity remain largely unknown. We study interfaces based on amorphous LAO top layers grown at room temperature (a-LAO/STO) and demonstrate a superconducting phase similar to c-LAO/STO, however, with a gate-tunable critical temperature of 460 mK. The dependence of the superconducting critical current on temperature, magnetic field, and back-gate-controlled doping is found to be consistently described by a model of a random array of Josephson-coupled superconducting domains
Extreme Sensitivity to Detuning for Globally Coupled Phase Oscillators
Peter Ashwin, Oleksandr Burylko, Yuri Maistrenko, and Oleksandr Popovych, Physical Review Letters, Vol. 96, p. 054102 (2006). "Copyright © 2006 by the American Physical Society."We discuss the sensitivity of a population of coupled oscillators to differences in their natural frequencies, i.e., to detuning. We argue that for three or more oscillators, one can get great sensitivity even if the coupling is strong. For N globally coupled phase oscillators we find there can be bifurcation to extreme sensitivity, where frequency locking can be destroyed by arbitrarily small detuning. This extreme sensitivity is absent for N=2, appears at isolated parameter values for N=3 and N=4, and can appear robustly for open sets of parameter values for ≥ 5 oscillators
Visible-light-enhanced gating effect at the LaAlO<sub>3</sub>/SrTiO<sub>3</sub> interface
Electrical field and light-illumination have been two most widely used
stimuli in tuning the conductivity of semiconductor devices. Via capacitive
effect electrical field modifies the carrier density of the devices, while
light-illumination generates extra carriers by exciting trapped electrons into
conduction band1. Here, we report on an unexpected light illumination enhanced
field effect in a quasi-two-dimensional electron gas (q2DEG) confined at the
LaAlO3/SrTiO3 (LAO/STO) interface which has been the focus of emergent
phenomenon exploration2-14. We found that light illumination greatly
accelerates and amplifies the field effect, driving the field-induced
resistance growth which originally lasts for thousands of seconds into an
abrupt resistance jump more than two orders of magnitude. Also, the
field-induced change in carrier density is much larger than that expected from
the capacitive effect, and can even be opposite to the conventional
photoelectric effect. This work expands the space for novel effect exploration
and multifunctional device design at complex oxide interfaces
High-temperature segmented thermoelectric oxide module using <em>p</em>-type Ca<sub>3</sub>Co<sub>4</sub>O<sub>9</sub> and <em>n</em>-type ZnAlO/CaMn<sub>0.95</sub>Nb<sub>0.05</sub>O<sub>3</sub> legs
Magnetic two-dimensional electron gas at the manganite-buffered LaAlO<sub>3</sub>/SrTiO<sub>3</sub> interface
Integrated stratigraphy of the Oligocene pelagic sequence in the Umbria-Marche basin (northeastern Apennines, Italy): A potential Global Stratotype Section and Point (GSSP) for the Rupelian/Chattian boundary.
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