Asymptotic Separation Between Adaptive and Non-adaptive Strategies in Quantum Channel Discrimination

Author(s):  
Farzin Salek ◽  
Masahito Hayashi ◽  
Andreas Winter
Author(s):  
Daniel E. Jones ◽  
Gabriele Riccardi ◽  
Cristian Antonelli ◽  
Michael Brodsky
Keyword(s):  

2019 ◽  
Vol 44 (2) ◽  
pp. 111-116 ◽  
Author(s):  
Vickie C. Kong ◽  
Amy Taylor ◽  
Peter Chung ◽  
Tim Craig ◽  
Tara Rosewall

2021 ◽  
Vol 13 (12) ◽  
pp. 6946
Author(s):  
Mercedes Cuevas López ◽  
Inmaculada Ávalos Ruiz ◽  
Emilio Jesús Lizarte Simón

Studies focusing on strategies for the cognitive regulation of emotions are gaining importance due to the development and perpetuation of psychopathologies. The obligatory home confinement imposed in response to the COVID-19 pandemic has led to new virtual learning methodologies. Objective: Our objective aimed to analyze and compare the cognitive emotional regulation of students from universities on the Spanish mainland with that of students attending the Universidad de Las Palmas de Gran Canaria. Methods: An online Emotional Regulation Questionnaire was applied, together with a survey covering the students’ beliefs about the pandemic, including information about their housing conditions and beliefs about online learning. The study included a sample of 1030 university students. Results: On the mainland and at Las Palmas de Gran Canaria, the students most frequently used adaptive strategies. Three of the strategies were used in both groups but to different extents (Acceptance, Positive reappraisal, Putting into perspective), while the other strategies were used in both groups to the same extent (Refocusing on planning, Positive refocusing, Rumination, Blaming others, Catastrophizing, Self-blame). Meanwhile, the results were quite similar regarding the students’ housing conditions and beliefs about the pandemic and online learning.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Bartosz Regula ◽  
Ryuji Takagi

AbstractQuantum channels underlie the dynamics of quantum systems, but in many practical settings it is the channels themselves that require processing. We establish universal limitations on the processing of both quantum states and channels, expressed in the form of no-go theorems and quantitative bounds for the manipulation of general quantum channel resources under the most general transformation protocols. Focusing on the class of distillation tasks — which can be understood either as the purification of noisy channels into unitary ones, or the extraction of state-based resources from channels — we develop fundamental restrictions on the error incurred in such transformations, and comprehensive lower bounds for the overhead of any distillation protocol. In the asymptotic setting, our results yield broadly applicable bounds for rates of distillation. We demonstrate our results through applications to fault-tolerant quantum computation, where we obtain state-of-the-art lower bounds for the overhead cost of magic state distillation, as well as to quantum communication, where we recover a number of strong converse bounds for quantum channel capacity.


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