4,181 research outputs found
Input-Output Relations in Optical Cavities: a Simple Point of View
In this work we present a very simple approach to input-output relations in
optical cavities, limiting ourselves to one- and two-photon states of the
field.
After field quantization, we derive the non-unitary transformation between
{\em Inside} and {\em Outside} annihilation and creation operators. Then we
express the most general two-photon state generated by {\em Inside} creation
operators, through base states generated by {\em Outside} creation operators.
After renormalization of coefficients of inside two-photon state, we calculate
the outside photon-number probability distribution in a general case. Finally
we treat with some detail the single mode and symmetrical cavity case.Comment: 34 pages, 5 figures jpg, LaTe
A Protocol for Generating Random Elements with their Probabilities
We give an AM protocol that allows the verifier to sample elements x from a
probability distribution P, which is held by the prover. If the prover is
honest, the verifier outputs (x, P(x)) with probability close to P(x). In case
the prover is dishonest, one may hope for the following guarantee: if the
verifier outputs (x, p), then the probability that the verifier outputs x is
close to p. Simple examples show that this cannot be achieved. Instead, we show
that the following weaker condition holds (in a well defined sense) on average:
If (x, p) is output, then p is an upper bound on the probability that x is
output. Our protocol yields a new transformation to turn interactive proofs
where the verifier uses private random coins into proofs with public coins. The
verifier has better running time compared to the well-known Goldwasser-Sipser
transformation (STOC, 1986). For constant-round protocols, we only lose an
arbitrarily small constant in soundness and completeness, while our public-coin
verifier calls the private-coin verifier only once
VIRTUAL MUSEUMS AS A MEANS FOR PROMOTION AND ENHANCEMENT OF CULTURAL HERITAGE
Abstract. The use of virtual reality and ICT in the museum context provides a new key to understand and promote Cultural Heritage: thanks to these technologies the user has the opportunity to experience without the need to come into contact with the real objects. For the museum institutions VR and ICT are a valuable tool that allows them to perform different cultural tasks, addressing the public in a much more effective way than has previously been possible. Especially through VR, it is possible to reconstruct the original context of the artworks through the interconnection of contents: the virtual visitor, while viewing the artwork, can consult useful contents for the learning process. Another revolutionary element introduced by the new technologies is linked to the possibility of creating virtual exhibitions through which it is possible to exhibit works that are not accessible or not visible. These reflections and these theoretical principles were the basis for the development of the project proposal presented in these pages, that was born as a collaboration between the R3D Lab of the Museo della Rappresentazione of University of Catania and the CIMS Lab of Carleton University, Ottawa. It consists in the creation of a virtual museum, the Timeless Museum, in order to create an educational experience, able to make the users reflect on topics such as the value of history, the sense of beauty, the relationship with our past and our future, the protection and transmission to future generations of the artistic heritage we have.</p
Experimental demonstration of fractional orbital angular momentum entanglement of two photons
The singular nature of a non-integer spiral phase plate allows easy
manipulation of spatial degrees of freedom of photon states. Using two such
devices, we have observed very high dimensional (D > 3700) spatial entanglement
of twin photons generated by spontaneous parametric down-conversion.Comment: submitted to Phys. Rev. Let
Design of Relaxation Digital-to-Analog Converters for Internet of Things Applications in 40nm CMOS
A 10-bit-400kS/s and a 10-bit-2MS/s Relaxation Digital to Analog Converters (ReDAC) in 40nm are presented in this paper. The two ReDACs operate from a 600mV power supply, occupy a silicon area of less than 1,000um^2. The first/second DAC achieve a maximum INL of 0.33/0.72 LSB and a maximum DNL of 0.2/1.27 LSB and 9.9/9.4 ENOB based on post-layout simulations. The average energy per conversion is less than 1.1/0.73pJ, corresponding to a FOM of 1.1/1.08 fJ/(conv. step), which make them well suited to Internet of Things (IoT) applications. (PDF) Design of Relaxation Digital-to-Analog Converters for Internet of Things Applications in 40nm CMOS. Available from: https://www.researchgate.net/publication/336552301_Design_of_Relaxation_Digital-to-Analog_Converters_for_Internet_of_Things_Applications_in_40nm_CMOS [accessed Nov 16 2019]
A Sub-Leakage pW-Power Hz-Range Relaxation Oscillator Operating with 0.3V-1.8V Unregulated Supply
A pW-power versatile relaxation oscillator operating from sub-threshold (0.3V) to nominal voltage (1.8V) is presented, having Hz-range frequency under sub-pF capacitor. The wide voltage and low sensitivity of frequency/absorbed current to the supply allow the suppression of the voltage regulator, and direct powering from harvesters (e.g., solar cell, thermal from machines) or 1.2-1.5V batteries. A 180nm testchip exhibits a frequency of 4 Hz , 10%/V supply sensitivity at 0.3-1.8V, 8-18pA current, 4%/°C thermal drift from -20°C to 40°C
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