Recently, it has been shown that excess noises generated or modified by chemical agents can be used to detect and identify chemicals with enhanced sensitivity and selectivity. Moreover thermal noise and its artificial versions (Johnson‐like noises) can be utilized as information carriers with peculiar properties. The first application is called Fluctuation‐Enhanced Sensing. The second class can be called Thermal Noise Informatics with relevant topics are Zero Power Classical Communication and (in the quantum limit) Zero‐Quantum Quantum Communication; Thermal Noise Driven Computing; and Totally Secure Classical Communication. In the paper version of this talk, we will briefly describe the scope of these fields and in the oral talk we also provide extended considerations and results.
Recently, it has been shown that excess noises generated or modified by chemical agents can be used to detect and identify chemicals with enhanced sensitivity and selectivity. Moreover thermal noise and its artificial versions (Johnson‐like noises) can be utilized as information carriers with peculiar properties. The first application is called Fluctuation‐Enhanced Sensing. The second class can be called Thermal Noise Informatics with relevant topics are Zero Power Classical Communication and (in the quantum limit) Zero‐Quantum Quantum Communication; Thermal Noise Driven Computing; and Totally Secure Classical Communication. In the paper version of this talk, we will briefly describe the scope of these fields and in the oral talk we also provide extended considerations and results.
Very recently, it has been shown that Gaussian thermal noise and its artificial versions (Johnson-like noises) can be utilized as an information carrier with peculiar properties therefore it may be proper to call this topic Thermal Noise Informatics. Zero Power (Stealth) Communication, Thermal Noise Driven Computing, and Totally Secure Classical Communication are relevant examples. In this paper, while we will briefly describe the first and the second subjects, we shall focus on the third subject, the secure classical communication via wire. This way of secure telecommunication utilizes the properties of Johnson(-like) noise and those of a simple Kirchhoff's loop. The communicator is unconditionally secure at the conceptual (circuit theoretical) level and this property is (so far) unique in communication systems based on classical physics. The communicator is superior to quantum alternatives in all known aspects, except the need of using a wire. In the idealized system, the eavesdropper can extract zero bit of information without getting uncovered. The scheme is naturally protected against the man-in-the-middle attack. The communication can take place also via currently used power lines or phone (wire) lines and it is not only a point-to-point communication like quantum channels but network-ready. We report that a pair of Kirchhoff-Loop-Johnson(-like)-Noise communicators, which is able to work over variable ranges, was designed and built. Tests have been carried out on a model-line with ranges beyond the ranges of any known direct quantum communication channel and they indicate unrivalled signal fidelity and security performance. This simple device has single-wire secure key generation/sharing rates of 0.1, 1, 10, and 100 bit/second for copper wires with diameters/ranges of 21 mm / 2000 km, 7 mm / 200 km, 2.3 mm / 20 km, and 0.7 mm / 2 km, respectively and it performs with 0.02% raw-bit error rate (99.98 % fidelity). The raw-bit security of this practical system significantly outperforms raw-bit quantum security. Current injection breaking tests show zero bit eavesdropping ability without setting on the alarm signal, therefore no multiple measurements are needed to build an error statistics to detect the eavesdropping as in quantum communication. Wire resistance based breaking tests of Bergou-Scheuer-Yariv type give an upper limit of eavesdropped raw bit ratio is 0.19 % and this limit is inversely proportional to the sixth power of cable diameter. Hao's breaking method yields zero (below measurement resolution) eavesdropping information.
We discuss the speed-error-heat triangle and related problems with rapidly increasing energy dissipation and error rate during miniaturization. These and the independently growing need of unconditional data security have provoked non-conventional approaches in the physics of informatics. Noise-based informatics is a potentially promising possibility which is the way how biological brains process the information. Recently, it has been shown that thermal noise and its electronically enhanced versions (Johnson-like noises) can be utilized as information carrier with peculiar properties. Relevant examples are Zero power (stealth) communication, Unconditionally secure communication with Johnson(-like) noise and Kirchhoff loop and Noise-driven computing. The zero power communication utilizes the equilibrium background noise in the channel to transfer information. The unconditionally secure communication is based on the properties of Johnson(-like) noise and those of a simple Kirchhoff's loop. The scheme utilizes on the robustness of classical information and the second law of thermodynamics. It uncovers active eavesdropping within a single clock period (no error statistics is required) and it is naturally protected against the man-in-the-middle attack. Further advantages of the scheme is that the circuitry can easily be integrated on computer chips, unconditionally secure computer processors, memories and other hardware can be realized.
A new physical way of communication, communication by the inherent background noise, is proposed which does not need net energy transfer in the information channel. The communicator devices do dissipate energy however they do not emit net energy into the channel, instead of that, they modulate the parameters of inherent spontaneous fluctuations in the channel. The new method can use two different mechanisms, thermal noise (Johnson-Nyquist noise) for classical communication, and vacuum fluctuations/zero point energy (quantum uncertainty noise) for quantum communication. The strongest advantage of the method that this is apparently the most hidden (stealth) way of communication, because it is using the inherent background noise for communication, therefore it is extremely difficult or impossible to discover its presence. Moreover, with proper wave-based arrangements, the sender and the receiver can easily detect eavesdropper activities, so that the eavesdropper is detected as soon as she extracts a single bit of information, thus the security of the method is at least as good or better than the security of quantum communication/quantum key distribution schemes. Finally, concerning practical applications, environmental noise, out of the fundamental/inherent fluctuations, can also be used for this kind of communication provided that is sufficiently stationary.
An alternative physical way of communication, communication by the inherent background noise, is proposed which does not need net energy transfer in the information channel. The communicator devices do dissipate energy; however, they do not emit net energy into the channel, instead of that, they modulate the parameters of inherent spontaneous fluctuations in the channel. The method can use two different mechanisms, thermal noise (Johnson–Nyquist noise) for classical communication, and vacuum fluctuations/zero-point energy (quantum uncertainty noise) for quantum communication. The strongest advantage of the method is that it is apparently the most hidden (stealth) way of communication, because it is using the inherent background noise for communication. Therefore, it is extremely difficult or impossible to discover its presence. With proper wave-based arrangements and specific conditions, the sender and the receiver can easily detect eavesdropper activities, so that the eavesdropper is detected as soon as she extracts a single bit of information, thus the security of the method is comparable to the security of quantum communication/quantum key distribution schemes. Finally, concerning practical applications, environmental noise, out of the fundamental/inherent fluctuations, can also be used for this kind of communication provided that is sufficiently stationary.
In quantum information and quantum computing, the carrier of information is a quantum system and information is encoded in its state. Secure communication schemes employ non‐orthogonal states that can not be discriminated with 100% probability of success. We briefly review various possible optimized state discrimination strategies since they provide a quantitative figure of merit for the acceptable noise level in quantum communication. We also report on recent results in two special areas. First, we consider discrimination between mixed quantum states. Second, we show that communication via completely unknown quantum states is possible and discuss programmable quantum state discriminators that accomplish this task optimally.
Quantum metamaterials offer multiple possibilities for the generation of non-classical light and the engineering of quantum and thermal noise. In our talk, we will review our latest advanced in the topic, describing how temporal metamaterials enable the generation of squeezed states of light, how antireflection temporal coatings facilitate quantum state frequency shifting and ultra-fast switching without thermal noise amplification, as well as the design of optical amplifiers with and enhanced noise performance based on noise correlations.