2,098 research outputs found
QuaIL, un projecte per potenciar les comunicacions a molt llarga distància mitjançant física quàntica i aprenentatge automàtic
No full textA grans distàncies, com les que separen Mart de la Terra, els senyals de llum s'atenuen extremadament i resulta molt difícil transmetre informació òpticament. Matteo Rosati té una beca Marie Skłodowska Curie en el Grup d'Informació Quàntica de la UAB per investigar el potencial de l'aprenentatge automàtic a les tecnologies de comunicació quàntica, i poder millorar la transmissió de missatges a aquesta escala.A grandes distancias, como las que separan Marte de la Tierra, las señales de luz se atenúan extremadamente y resulta muy difícil transmitir información ópticamente. Matteo Rosati tiene una beca Marie Skłodowska Curie en el Grupo de Información Cuántica de la UAB para investigar el potencial del aprendizaje automático en las tecnologías de comunicación cuántica, y poder mejorar la transmisión de mensajes a esta escala.Over long distances, such as those that separate Mars from Earth, the light signals are extremely dimmed and it is very difficult to transmit information optically. Matteo Rosati has a Marie Skłodowska Curie fellow in the UAB Quantum Information Group to investigate the potential of Machine Learning in Quantum Communication technologies, and to improve the transmission of messages at this scale
QuaIL, un projecte per potenciar les comunicacions a molt llarga distància mitjançant física quàntica i aprenentatge automàtic
No full textA grans distàncies, com les que separen Mart de la Terra, els senyals de llum s'atenuen extremadament i resulta molt difícil transmetre informació òpticament. Matteo Rosati té una beca Marie Skłodowska Curie en el Grup d'Informació Quàntica de la UAB per investigar el potencial de l'aprenentatge automàtic a les tecnologies de comunicació quàntica, i poder millorar la transmissió de missatges a aquesta escala.A grandes distancias, como las que separan Marte de la Tierra, las señales de luz se atenúan extremadamente y resulta muy difícil transmitir información ópticamente. Matteo Rosati tiene una beca Marie Skłodowska Curie en el Grupo de Información Cuántica de la UAB para investigar el potencial del aprendizaje automático en las tecnologías de comunicación cuántica, y poder mejorar la transmisión de mensajes a esta escala.Over long distances, such as those that separate Mars from Earth, the light signals are extremely dimmed and it is very difficult to transmit information optically. Matteo Rosati has a Marie Skłodowska Curie fellow in the UAB Quantum Information Group to investigate the potential of Machine Learning in Quantum Communication technologies, and to improve the transmission of messages at this scale
Com avaluar el rendiment dels dispositius de comunicació quàntica
No full textMatteo Rosati, del Grup d'Informació Quàntica, ha calculat els límits superiors de la informació quàntica que pot ser transmesa entre dos dispositius. La investigació, publicada recentment a Nature Communications, permet avaluar el rendiment teòric dels dispositius de comunicació quàntica, tant actuals com futurs.Matteo Rosati, del Grupo de Información Cuántica, ha calculado los límites superiores de la información cuántica que puede ser transmitida entre dos dispositivos. La investigación, publicada recientemente en Nature Communications, permite evaluar el rendimiento teórico de los dispositivos de comunicación cuántica, tanto actuales como futuros.Matteo Rosati, from the Grup d'Informació Quàntica, has computed upper bounds on the maximum quantum information that can be transmitted through space. The research, recently published in Nature Communications, allows to evaluate the performance of present and future quantum communication devices for all practical purposes
Multi-pulse Fourier codes for bit transmission at the quantum limit
No full textBit-transmission can be enhanced by the use of quantum detection techniques, realizing a joint-detection receiver (JDR) that is able to decode transmitted signals via a collective operation and achieve the Holevo channel capacity. Explicit JDR designs proposed so far employ the Hadamard or Fourier transform to perform a phase-to-intensity translation of the information encoding, effectively falling in the class of on-off-keying (OOK) modulation techniques; they improve over classical decoders but fall short of the Holevo capacity, particularly at large signal mean photon number n ≳ 1 . Here we introduce new families of decoders based on multi-pulse and multi-level codes. We compute the rate of these codes exactly, and provide a comprehensive study of their performance. We show that multi-pulse codes can approach the rate of OOK closely, providing a simplified design for quantum-enhanced communication in the photon-starved regime; furthermore, multi-level codes can approach generalized-OOK strategies with multiple pulse types, thus they can be employed in the larger photon-number regime
The n-shot classical capacity of the quantum erasure channel
No full textWe compute the n -shot classical capacity of the quantum erasure channel, providing upper bounds and almost-matching lower bounds for it, the latter achievable via large-minimum-distance classical linear codes for any n . The protocols are in full product form, i.e. no entanglement is needed either at the encoder or decoder to attain the capacity, and they explicitly adapt to the transition between different error regimes as the erasure probability increases. Finally, we show that our upper and lower bounds on the capacity are tighter than those obtainable from the general theory of finite-size capacity via generalized divergences
Com avaluar el rendiment dels dispositius de comunicació quàntica
No full textMatteo Rosati, del Grup d'Informació Quàntica, ha calculat els límits superiors de la informació quàntica que pot ser transmesa entre dos dispositius. La investigació, publicada recentment a Nature Communications, permet avaluar el rendiment teòric dels dispositius de comunicació quàntica, tant actuals com futurs.Matteo Rosati, del Grupo de Información Cuántica, ha calculado los límites superiores de la información cuántica que puede ser transmitida entre dos dispositivos. La investigación, publicada recientemente en Nature Communications, permite evaluar el rendimiento teórico de los dispositivos de comunicación cuántica, tanto actuales como futuros.Matteo Rosati, from the Grup d'Informació Quàntica, has computed upper bounds on the maximum quantum information that can be transmitted through space. The research, recently published in Nature Communications, allows to evaluate the performance of present and future quantum communication devices for all practical purposes
A learning theory for quantum photonic processors and beyond
No full textWe consider the tasks of learning quantum states, measurements and channels generated by continuous-variable (CV) quantum circuits. This family of circuits is suited to describe optical quantum technologies and in particular it includes state-of-the-art photonic processors capable of showing quantum advantage. We define classes of functions that map classical variables, encoded into the CV circuit parameters, to outcome probabilities evaluated on those circuits. We then establish efficient learnability guarantees for such classes, by computing bounds on their pseudo-dimension or covering numbers, showing that CV quantum circuits can be learned with a sample complexity that scales polynomially with the circuit\u27s size, i.e., the number of modes. Our results show that CV circuits can be trained efficiently using a number of training samples that, unlike their finite-dimensional counterpart, does not scale with the circuit depth.27+5 pages, 2 figure
Performance of Coherent Frequency-Shift Keying for Classical Communication on Quantum Channels
No full textWe evaluate the performance of coherent frequency-shift keying (CFSK) [1], [2] alphabets for communication on quantum channels. We show that, contrarily to what previously thought, the square-root-measurement (SRM) is sub-optimal for discriminating CFSK states. Furthermore, we compute the maximum information transmission rate of the CFSK alphabet, observing that it employs at least as many frequency modes as the signal states, and compare it with standard phase-shift-keying. Finally, we introduce a discretized CFSK alphabet with higher mode-efficiency, exhibiting comparable error-probability performance with respect to CFSK and better rate performance. Our results suggest the existence of a tradeoff between the CFSK reduced error-probability and its mode efficiency
M. Rosati, The Making of a Postsecular Society. A Durkheimian Approach to Memory, Pluralism, and Religion in Turkey (Farnham, Ashgate, 2014)
No full textrecensione del volume M. Rosati, The Making of a Postsecular Society. A Durkheimian Approach to Memory, Pluralism, and Religion in Turkey (Farnham, Ashgate, 2014)
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