Spin rotator and shot noise in graphene-based multi-barrier nanostructure

2012 ◽  
Vol 85 (10) ◽  
Author(s):  
Q.P. Wu ◽  
X.D. He ◽  
Z.F. Liu
Keyword(s):  
1999 ◽  
Vol 09 (PR2) ◽  
pp. Pr2-23
Author(s):  
L. Saminadayar ◽  
A. Kumar ◽  
D. C. Glattli ◽  
Y. Jin ◽  
B. Etienne
Keyword(s):  

1984 ◽  
Author(s):  
A. J. Lemoine ◽  
M. L. Wenocur

Author(s):  
A. G. Wright

Standards laboratories can provide a photocathode calibration for quantum efficiency, as a function of wavelength, but their measurements are performed with the photomultiplier operating as a photodiode. Each photoelectron released makes a contribution to the photocathode current but, if it is lost or fails to create secondary electrons at d1, it makes no contribution to anode current. This is the basis of collection efficiency, F. The anode detection efficiency, ε‎, allied to F, refers to the counting efficiency of output pulses. The standard method for determining F involves photocurrent, anode current, count rate, and the use of highly attenuating filters; F may also be measured using methods based on single-electron responses (SERs), shot noise, or the SER at the first dynode.


2016 ◽  
Vol 41 (17) ◽  
pp. 3932 ◽  
Author(s):  
Guofeng Zhang ◽  
Hanjie Zhu

Author(s):  
Harold Phelippeau ◽  
Hugues Talbot ◽  
Mohamed Akil ◽  
Stefan Bara
Keyword(s):  

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Gaetano Frascella ◽  
Sascha Agne ◽  
Farid Ya. Khalili ◽  
Maria V. Chekhova

AbstractAmong the known resources of quantum metrology, one of the most practical and efficient is squeezing. Squeezed states of atoms and light improve the sensing of the phase, magnetic field, polarization, mechanical displacement. They promise to considerably increase signal-to-noise ratio in imaging and spectroscopy, and are already used in real-life gravitational-wave detectors. But despite being more robust than other states, they are still very fragile, which narrows the scope of their application. In particular, squeezed states are useless in measurements where the detection is inefficient or the noise is high. Here, we experimentally demonstrate a remedy against loss and noise: strong noiseless amplification before detection. This way, we achieve loss-tolerant operation of an interferometer fed with squeezed and coherent light. With only 50% detection efficiency and with noise exceeding the level of squeezed light more than 50 times, we overcome the shot-noise limit by 6 dB. Sub-shot-noise phase sensitivity survives up to 87% loss. Application of this technique to other types of optical sensing and imaging promises a full use of quantum resources in these fields.


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