scholarly journals Engineering Classical Capacity of Generalized Pauli Channels with Admissible Memory Kernels

Entropy ◽  
2021 ◽  
Vol 23 (11) ◽  
pp. 1382
Author(s):  
Katarzyna Siudzińska ◽  
Arpan Das ◽  
Anindita Bera

In this paper, we analyze the classical capacity of the generalized Pauli channels generated via memory kernel master equations. For suitable engineering of the kernel parameters, evolution with non-local noise effects can produce dynamical maps with a higher capacity than a purely Markovian evolution. We provide instructive examples for qubit and qutrit evolution. Interestingly, similar behavior is not observed when analyzing time-local master equations.

2010 ◽  
Vol 81 (6) ◽  
Author(s):  
L. Mazzola ◽  
E.-M. Laine ◽  
H.-P. Breuer ◽  
S. Maniscalco ◽  
J. Piilo

2020 ◽  
Vol 22 (8) ◽  
pp. 083011 ◽  
Author(s):  
Nina Megier ◽  
Andrea Smirne ◽  
Bassano Vacchini
Keyword(s):  

2016 ◽  
Vol 93 (5) ◽  
Author(s):  
Salvatore Lorenzo ◽  
Francesco Ciccarello ◽  
G. Massimo Palma

2011 ◽  
Vol 09 (supp01) ◽  
pp. 129-138 ◽  
Author(s):  
DARIUSZ CHRUŚCIŃSKI ◽  
ANDRZEJ KOSSAKOWSKI

We analyze a local approach to the non-Markovian evolution of open quantum systems. It turns out that any dynamical map representing evolution of such a system may be described either by non-local master equation with memory kernel or equivalently by equation which is local in time. The price one pays for the local approach is that the corresponding generator might be highly singular and it keeps the memory about the starting point "t0". This is the very essence of non-Markovianity. We illustrate a local approach by simple examples.


Author(s):  
Zhifeng Shao

Recently, low voltage (≤5kV) scanning electron microscopes have become popular because of their unprecedented advantages, such as minimized charging effects and smaller specimen damage, etc. Perhaps the most important advantage of LVSEM is that they may be able to provide ultrahigh resolution since the interaction volume decreases when electron energy is reduced. It is obvious that no matter how low the operating voltage is, the resolution is always poorer than the probe radius. To achieve 10Å resolution at 5kV (including non-local effects), we would require a probe radius of 5∽6 Å. At low voltages, we can no longer ignore the effects of chromatic aberration because of the increased ratio δV/V. The 3rd order spherical aberration is another major limiting factor. The optimized aperture should be calculated as


Author(s):  
Zhifeng Shao ◽  
A.V. Crewe

For scanning electron microscopes, it is plausible that by lowering the primary electron energy, one can decrease the volume of interaction and improve resolution. As shown by Crewe /1/, at V0 =5kV a 10Å resolution (including non-local effects) is possible. To achieve this, we would need a probe size about 5Å. However, at low voltages, the chromatic aberration becomes the major concern even for field emission sources. In this case, δV/V = 0.1 V/5kV = 2x10-5. As a rough estimate, it has been shown that /2/ the chromatic aberration δC should be less than ⅓ of δ0 the probe size determined by diffraction and spherical aberration in order to neglect its effect. But this did not take into account the distribution of electron energy. We will show that by using a wave optical treatment, the tolerance on the chromatic aberration is much larger than we expected.


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