Nanoscale continuous transition from monoclinic to ferroelectric orthorhombic inside HfO2 nanocrystals stabilized by HfO2 capping and self-controlled Ge doping

2021 ◽  
Author(s):  
Catalin Palade ◽  
Ana-Maria Lepadatu ◽  
Adrian Slav ◽  
Ovidiu Cojocaru ◽  
Alin Iuga ◽  
...  
Keyword(s):  
Continuous Transition ◽  
Ferroelectric Memories ◽  
Ge Doping

Orthorhombic HfO2 exhibits nanoscale ferroelectricity that opens the perspective of ultra-scalable CMOS integration of ferroelectric memories. However, many aspects of the metastable orthorhombic crystallization mechanisms need still to be elucidated...

scholarly journals Transport of pseudothermal photons through an anharmonic cavity

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dmitriy S. Shapiro
Keyword(s):  
Pauli Principle ◽  
Optical Systems ◽  
Frequency Noise ◽  
Continuous Transition ◽  
Noise Current ◽  
Nonperturbative Solution ◽  
Occupation Numbers ◽  
Fundamental Reason ◽  
The Rich ◽  
Quantum Optical

AbstractUnder nonequilibrium conditions, quantum optical systems reveal unusual properties that might be distinct from those in condensed matter. The fundamental reason is that photonic eigenstates can have arbitrary occupation numbers, whereas in electronic systems these are limited by the Pauli principle. Here, we address the steady-state transport of pseudothermal photons between two waveguides connected through a cavity with Bose–Hubbard interaction between photons. One of the waveguides is subjected to a broadband incoherent pumping. We predict a continuous transition between the regimes of Lorentzian and Gaussian chaotic light emitted by the cavity. The rich variety of nonequilibrium transport regimes is revealed by the zero-frequency noise. There are three limiting cases, in which the noise-current relation is characterized by a power-law, $$S\propto J^\gamma$$ S ∝ J γ . The Lorentzian light corresponds to Breit-Wigner-like transmission and $$\gamma =2$$ γ = 2 . The Gaussian regime corresponds to many-body transport with the shot noise ($$\gamma =1$$ γ = 1 ) at large currents; at low currents, however, we find an unconventional exponent $$\gamma =3/2$$ γ = 3 / 2 indicating a nontrivial interplay between multi-photon transitions and incoherent pumping. The nonperturbative solution for photon dephasing is obtained in the framework of the Keldysh field theory and Caldeira-Leggett effective action. These findings might be relevant for experiments on photon blockade in superconducting qubits, thermal states transfer, and photon statistics probing.

scholarly journals Outflowing Envelopes From Stars at Arbitrary Optical Depths a New Approach to the Problem

1998 ◽  
Vol 11 (1) ◽  
pp. 381-381
Author(s):  
A.V. Dorodnitsyn
Keyword(s):  
Differential Equations ◽  
Massive Star ◽  
System Of Differential Equations ◽  
Continuous Transition ◽  
Satisfactory Description ◽  
Sonic Point ◽  
New Approach ◽  
Star Evolution ◽  
Matter Flux ◽  
Massive Star Evolution

We have considered a stationary outflowing envelope accelerated by the radiative force in arbitrary optical depth case. Introduced approximations provide satisfactory description of the behavior of the matter flux with partially separated radiation at arbitrary optical depths. The obtained systemof differential equations provides a continuous transition of the solution between optically thin and optically thick regions. We analytically derivedapproximate representation of the solution at the vicinity of the sonic point. Using this representation we numerically integrate the system of equations from the critical point to the infinity. Matching the boundary conditions we obtain solutions describing the problem system of differential equations. The theoretical approach advanced in this work could be useful for self-consistent simulations of massive star evolution with mass loss.

scholarly journals Nanoscale bubble domains with polar topologies in bulk ferroelectrics

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Jie Yin ◽  
Hongxiang Zong ◽  
Hong Tao ◽  
Xuefei Tao ◽  
Haijun Wu ◽  
...  
Keyword(s):  
Physical Properties ◽  
Bulk Material ◽  
Condensed Matter ◽  
Time Dependent ◽  
Morphology Evolution ◽  
Contrast Imaging ◽  
Ferroelectric Films ◽  
Modulated Phases ◽  
Ferroelectric Memories ◽  
Z Contrast

AbstractMultitudinous topological configurations spawn oases of many physical properties and phenomena in condensed-matter physics. Nano-sized ferroelectric bubble domains with various polar topologies (e.g., vortices, skyrmions) achieved in ferroelectric films present great potential for valuable physical properties. However, experimentally manipulating bubble domains has remained elusive especially in the bulk form. Here, in any bulk material, we achieve self-confined bubble domains with multiple polar topologies in bulk Bi0.5Na0.5TiO3 ferroelectrics, especially skyrmions, as validated by direct Z-contrast imaging. This phenomenon is driven by the interplay of bulk, elastic and electrostatic energies of coexisting modulated phases with strong and weak spontaneous polarizations. We demonstrate reversable and tip-voltage magnitude/time-dependent donut-like domain morphology evolution towards continuously and reversibly modulated high-density nonvolatile ferroelectric memories.

Super-elastic ferroelectric single-crystal membrane with continuous electric dipole rotation

Science ◽  
2019 ◽  
Vol 366 (6464) ◽  
pp. 475-479 ◽  
Author(s):  
Guohua Dong ◽  
Suzhi Li ◽  
Mouteng Yao ◽  
Ziyao Zhou ◽  
Yong-Qiang Zhang ◽  
...  
Keyword(s):  
Energy Landscape ◽  
Domain Engineering ◽  
Bending Test ◽  
Dynamic Evolution ◽  
Brittle Deformation ◽  
Continuous Transition ◽  
Flexible Sensors ◽  
Mismatch Stress ◽  
Ferroelectric Single Crystal

Ferroelectrics are usually inflexible oxides that undergo brittle deformation. We synthesized freestanding single-crystalline ferroelectric barium titanate (BaTiO3) membranes with a damage-free lifting-off process. Our BaTiO3 membranes can undergo a ~180° folding during an in situ bending test, demonstrating a super-elasticity and ultraflexibility. We found that the origin of the super-elasticity was from the dynamic evolution of ferroelectric nanodomains. High stresses modulate the energy landscape markedly and allow the dipoles to rotate continuously between the a and c nanodomains. A continuous transition zone is formed to accommodate the variant strain and avoid high mismatch stress that usually causes fracture. The phenomenon should be possible in other ferroelectrics systems through domain engineering. The ultraflexible epitaxial ferroelectric membranes could enable many applications such as flexible sensors, memories, and electronic skins.

A Secure Robust and Privacy Enhanced Mobile Healthcare Framework

2018 ◽  
Vol 15 (3) ◽  
pp. 61-81
Author(s):  
Hisham M. Alsaghier ◽  
Shaik Shakeel Ahamad
Keyword(s):  
Health Systems ◽  
Mobile Health ◽  
Integrated Circuit ◽  
Cost Effective ◽  
Healthcare Services ◽  
Healthcare Industry ◽  
Continuous Transition ◽  
Trusted Platform Module ◽  
Mobile Healthcare ◽  
Mobile Health Systems

This article describes how the exponential growth of mobile applications has changed the way healthcare services function, and mobile healthcare using the Cloud is the most promising technology for healthcare industry. The mobile healthcare industry is in a continuous transition phase that requires continual innovation. There has been identified some of the challenges in the area of security protocols for mobile health systems which still need to be addressed in the future to enable cost-effective, secure and robust mobile health systems. This article addresses these challenges by proposing a secure robust and privacy-enhanced mobile healthcare framework (SRPF) by adopting a Community Cloud (CC), WPKI cryptosystems, Universal Integrated Circuit Cards (UICCs) and a Trusted Platform Module (TPM). All the security properties are provided within this framework. SRPF overcomes replay attacks, Man in the Middle (MITM) Attacks, Impersonation attacks and Multi-Protocol attacks as SRPF was successfully verified using a scyther tool and by BAN logic.

A hydrochemical and isotopic case study around a near surface radioactive waste disposal

2007 ◽  
Vol 95 (1) ◽  
Author(s):  
Zs. Szántó ◽  
É. Svingor ◽  
I. Futó ◽  
L. Palcsu ◽  
M. Molnár ◽  
...  
Keyword(s):  
Radioactive Waste ◽  
Waste Treatment ◽  
Radioactive Waste Disposal ◽  
Ion Chemistry ◽  
Continuous Transition ◽  
Near Surface ◽  
Disposal Facility ◽  
Treatment And Disposal ◽  
Site Characterisation

As part of the site characterisation program for the near surface radioactive waste treatment and disposal facility (RWTDF) at Püspökszilágy, Hungary, water quality and environmental isotope investigations have been carried out. Water samples for major ion chemistry, tritium,The chemical composition of groundwaters presented a continuous transition from waters situated on one side to waters on the top and on the other slope of the disposal suggesting the mixing of the three hydrochemical “endmembers”.Most of δ

scholarly journals Direct Observations of Retention Failure in Ferroelectric Memories

2012 ◽  
Vol 24 (8) ◽  
pp. 1106-1110 ◽  
Author(s):  
Peng Gao ◽  
Christopher T. Nelson ◽  
Jacob R. Jokisaari ◽  
Yi Zhang ◽  
Seung-Hyub Baek ◽  
...  
Keyword(s):  
Direct Observations ◽  
Ferroelectric Memories

New electrode-barrier structures for high density ferroelectric memories

2001 ◽  
Vol 72 (1) ◽  
pp. 13-20 ◽  
Author(s):  
R. Vedula ◽  
C.S. Desu ◽  
S. Tirumala ◽  
H.D. Bhatt ◽  
S.B. Desu ◽  
...  
Keyword(s):  
High Density ◽  
Ferroelectric Memories

scholarly journals Ferroelectric HfO2-based materials for next-generation ferroelectric memories

2016 ◽  
Vol 06 (02) ◽  
pp. 1630003 ◽  
Author(s):  
Zhen Fan ◽  
Jingsheng Chen ◽  
John Wang
Keyword(s):  
Random Access ◽  
Complementary Metal Oxide Semiconductor ◽  
Ferroelectric Materials ◽  
Oxide Semiconductor ◽  
Next Generation ◽  
New Class ◽  
Generation Cost ◽  
Potential Applications ◽  
Cost Efficient ◽  
Ferroelectric Memories

Ferroelectric random access memory (FeRAM) based on conventional ferroelectric perovskites, such as Pb(Zr,Ti)O3 and SrBi2Ta2O9, has encountered bottlenecks on memory density and cost, because those conventional perovskites suffer from various issues mainly including poor complementary metal-oxide-semiconductor (CMOS)-compatibility and limited scalability. Next-generation cost-efficient, high-density FeRAM shall therefore rely on a material revolution. Since the discovery of ferroelectricity in Si:HfO2 thin films in 2011, HfO2-based materials have aroused widespread interest in the field of FeRAM, because they are CMOS-compatible and can exhibit robust ferroelectricity even when the film thickness is scaled down to below 10 nm. A review on this new class of ferroelectric materials is therefore of great interest. In this paper, the most appealing topics about ferroelectric HfO2-based materials including origins of ferroelectricity, advantageous material properties, and current and potential applications in FeRAM, are briefly reviewed.

Sign in / Sign up

Export Citation Format

Share Document