scholarly journals Ultrafast reorientation of the Néel vector in antiferromagnetic Dirac semimetals

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Atsushi Ono ◽  
Sumio Ishihara
Keyword(s):  
Real Time ◽  
Ultrafast Dynamics ◽  
Dirac Fermions ◽  
Spin Orbit ◽  
Fundamental Physics ◽  
Time Dynamics ◽  
Time Symmetry ◽  
Optical Effects ◽  
Dirac Semimetals ◽  
A Current

AbstractAntiferromagnets exhibit distinctive characteristics such as ultrafast dynamics and robustness against perturbative fields, thereby attracting considerable interest in fundamental physics and technological applications. Recently, it was revealed that the Néel vector can be switched by a current-induced staggered (Néel) spin-orbit torque in antiferromagnets with the parity-time symmetry, and furthermore, a nonsymmorphic symmetry enables the control of Dirac fermions. However, the real-time dynamics of the magnetic and electronic structures remain largely unexplored. Here, we propose a theory of the ultrafast dynamics in antiferromagnetic Dirac semimetals and show that the Néel vector is rotated in the picosecond timescale by the terahertz-pulse-induced Néel spin-orbit torque and other torques originating from magnetic anisotropies. This reorientation accompanies the modulation of the mass of Dirac fermions and can be observed in real time by the magneto-optical effects. Our results provide a theoretical basis for emerging ultrafast antiferromagnetic spintronics combined with the topological aspects of materials.

scholarly journals Investigations, actions and learning from an outbreak of SARS-CoV-2 infection among healthcare workers in the United Kingdom

2020 ◽  
pp. 175717742097679
Author(s):  
Kordo Saeed ◽  
Emanuela Pelosi ◽  
Nitin Mahobia ◽  
Nicola White ◽  
Christopher Labdon ◽  
...  
Keyword(s):  
Real Time ◽  
Healthcare Workers ◽  
Healthcare Facility ◽  
Rt Pcr ◽  
Serum Samples ◽  
The United Kingdom ◽  
Key Issues ◽  
Current Infection ◽  
Polymerase Chain ◽  
A Current

Background: We report an outbreak of SARS coronavirus-2 (SARS-CoV-2) infection among healthcare workers (HCW) in an NHS elective healthcare facility. Methodology: A narrative chronological account of events after declaring an outbreak of SARS-CoV-2 among HCWs. As part of the investigations, HCWs were offered testing during the outbreak. These were: (1) screening by real-time reverse transcriptase polymerase chain reaction (RT- PCR) to detect a current infection; and (2) serum samples to determine seroprevalence. Results: Over 180 HCWs were tested by real-time RT-PCR for SARS-CoV-2 infection. The rate of infection was 15.2% (23.7% for clinical or directly patient-facing HCWs vs. 4.8% in non-clinical non-patient-facing HCWs). Of the infected HCWs, 57% were asymptomatic. Seroprevalence (SARS-CoV-2 IgG) among HCWs was 13%. It was challenging to establish an exact source for the outbreak. The importance of education, training, social distancing and infection prevention practices were emphasised. Additionally, avoidance of unnecessary transfer of patients and minimising cross-site working for staff and early escalation were highlighted. Establishing mass and regular screening for HCWs are also crucial to enabling the best care for patients while maintaining the wellbeing of staff. Conclusion: To our knowledge, this is the first UK outbreak report among HCWs and we hope to have highlighted some key issues and learnings that can be considered by other NHS staff and HCWs globally when dealing with such a task in future.

Real-Time Tem Studies of Electromigration in Submicron Aluminum Runners

1995 ◽  
Vol 391 ◽  
Author(s):  
S. P. Riege ◽  
A. W. Hunt ◽  
J. A. Prybyla
Keyword(s):  
Real Time ◽  
Joule Heating ◽  
Current Density ◽  
Constant Voltage ◽  
Sample Design ◽  
A Current

AbstractDirect real-time observations of electromigration (EM) in submicron Al interconnects were made using a special sample-stage which allowed TEM observations to be recorded while simultaneously heating and passing current through the sample. The samples consisted of 4000 Å thick Al(0.5wt%Cu) patterned over a TEM-transparent window into five runners in parallel, with linewidths 0.2, 0.3, 0.5, 0.8, and 1.0 μm. Both passivated and unpassivated samples were examined. A current density of 2 x 106A/cm2 was used with temperatures ranging from 200 - 350°C. The experiments were done using constant voltage testing, and we used a special sample design which dramatically minimized Joule-heating. Our approach has allowed us to directly observe voids form, grow, migrate, pin, fail a runner, and heal, all with respect to the detailed local microstructure of the runners.

A current meter with intelligent data system, environmental sensors and real-time telemetry

1990 ◽  
Author(s):  
J.D. Irish ◽  
G.J. Needell ◽  
K. Morey ◽  
J. Wood ◽  
K.C. Baldwin
Keyword(s):  
Real Time ◽  
Data System ◽  
Environmental Sensors ◽  
A Current

scholarly journals Real-time dynamics in the one-dimensional Hubbard model

2014 ◽  
Vol 90 (24) ◽  
Author(s):  
Luis Seabra ◽  
Fabian H. L. Essler ◽  
Frank Pollmann ◽  
Imke Schneider ◽  
Thomas Veness
Keyword(s):  
Hubbard Model ◽  
Real Time ◽  
One Dimensional ◽  
Time Dynamics ◽  
The One

scholarly journals Computer Algebra for Real-Time Dynamics of Robots with Large Numbers of Joints

2004 ◽  
pp. 278-285 ◽  
Author(s):  
Ramutis Bansevicius ◽  
Algimantas Cepulkauskas ◽  
Regina Kulvietiene ◽  
Genadijus Kulvietis
Keyword(s):  
Real Time ◽  
Computer Algebra ◽  
Time Dynamics ◽  
Large Numbers

Magneto-optical properties of defect centres in alkali halide crystals

1967 ◽  
Vol 300 (1460) ◽  
pp. 78-93 ◽  
Keyword(s):  
Optical Absorption ◽  
Silver Atom ◽  
Alkali Halides ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Coupling Constant ◽  
Absorption Bands ◽  
Optical Effects ◽  
Alkali Halide Crystals ◽  
Defect Centres

Zeeman spectroscopy is not practicable for the investigation of the structure of electronic conventional states which give rise to broad optical absorption bands in solids. We have investigated the application of Faraday rotation and circular dichroism techniques to absorption bands of neutral silver atoms and F centres in alkali halides. These centres give rise to optical absorption bands due to transitions of the type 2 S → 2 P which are 2000 to 6000 cm -1 in width because, in part, of strong coupling to lattice phonons. A discussion is given of information which may be obtained concerning the electonic states involved in the 2 S → 2 P transition by analysis of the magneto-optical effects by the method of moments. It is shown, for example, that the spin-orbit coupling constant of the 2 P state of the silver atom is reduced from 613 cm -1 in the free state to 365 cm -1 in KCl, to 102 cm -1 in KBr and to an unmeasurably small value in KI. This cancellation of spin-orbit interaction of the silver atom is assigned to symmetry allowed admixtures of lattice ion wavefunctions into the 2 P state.

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