The quantum vacuum as the origin of the speed of light
... The vacuum permeability μ0 , the vacuum permittivity 0 , and the speed of light in vacuum c are widely considered as being fundamental constants and their values, escaping any physical explanation, are commonly assumed to be invariant in space and time. In this paper, we propose a mechanism based u ...
... The vacuum permeability μ0 , the vacuum permittivity 0 , and the speed of light in vacuum c are widely considered as being fundamental constants and their values, escaping any physical explanation, are commonly assumed to be invariant in space and time. In this paper, we propose a mechanism based u ...
QUANTROPY 1. Introduction There is a famous analogy between
... from a principle of maximum entropy with amplitudes—or as they prefer to put it, complex probabilities—replacing probabilities. However, seeking to derive amplitudes for paths in quantum mechanics from a maximum principle is not quite correct. Quantum mechanics is rife with complex numbers, and it m ...
... from a principle of maximum entropy with amplitudes—or as they prefer to put it, complex probabilities—replacing probabilities. However, seeking to derive amplitudes for paths in quantum mechanics from a maximum principle is not quite correct. Quantum mechanics is rife with complex numbers, and it m ...
The symmetrized quantum potential and space as a direct
... last century. Gödel and Einstein opened new perspectives regarding definition and experience of time. They have been discussing the possibility that there is no time in the universe as science experiences it, that time into which material changes run exists only as a concept of our mind. In 1949, Gö ...
... last century. Gödel and Einstein opened new perspectives regarding definition and experience of time. They have been discussing the possibility that there is no time in the universe as science experiences it, that time into which material changes run exists only as a concept of our mind. In 1949, Gö ...
W. Pauli - Fisica Fundamental
... A more serious difficulty, raising a matter of principle, is however the connexion of these ideas with the correspondence principle which is well known to be a necessary means to explain the selection rules for the quantum numbers k1, j, and m and the polarisation of the Zeeman components. It is, to ...
... A more serious difficulty, raising a matter of principle, is however the connexion of these ideas with the correspondence principle which is well known to be a necessary means to explain the selection rules for the quantum numbers k1, j, and m and the polarisation of the Zeeman components. It is, to ...
Quantum Level Structures and Nonlinear Classical Dynamics
... given system, far from the normal mode regime, there is a clear need for some interpretive structure. Fortunately there are many cases in which the eigenvalues fall into polyads (1, 2, 5–7), but there can also be subdivisions within a polyad. For example, the local mode polyads of H2 O divide into a ...
... given system, far from the normal mode regime, there is a clear need for some interpretive structure. Fortunately there are many cases in which the eigenvalues fall into polyads (1, 2, 5–7), but there can also be subdivisions within a polyad. For example, the local mode polyads of H2 O divide into a ...
part 1
... Searching for Coherences Using the same Fourier transform technique as in the density matrix measurement, we have performed a search of our atomic beam source for any intrinsic momentum coherences (which would appear as amplitude modulation) up to a frequency of 100 kHz. To do this, we simply looked ...
... Searching for Coherences Using the same Fourier transform technique as in the density matrix measurement, we have performed a search of our atomic beam source for any intrinsic momentum coherences (which would appear as amplitude modulation) up to a frequency of 100 kHz. To do this, we simply looked ...
Quasidistributions in nonlinear quantum optics
... It is well known from the papers by R.J. Glauber [1, 2] published in 1963, founding the modern quantum optics, that optical processes having completely quantum behavior, i.e. having no classical analogue, are described by means of quasidistributions, e.g. using the weighting function in the diagonal ...
... It is well known from the papers by R.J. Glauber [1, 2] published in 1963, founding the modern quantum optics, that optical processes having completely quantum behavior, i.e. having no classical analogue, are described by means of quasidistributions, e.g. using the weighting function in the diagonal ...
Quantum key distribution
Quantum key distribution (QKD) uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the most well known example of the group of quantum cryptographic tasks.An important and unique property of quantum key distribution is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented which detects eavesdropping. If the level of eavesdropping is below a certain threshold, a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about it), otherwise no secure key is possible and communication is aborted.The security of encryption that uses quantum key distribution relies on the foundations of quantum mechanics, in contrast to traditional public key cryptography which relies on the computational difficulty of certain mathematical functions, and cannot provide any indication of eavesdropping at any point in the communication process, or any mathematical proof as to the actual complexity of reversing the one-way functions used. QKD has provable security based on information theory, and forward secrecy.Quantum key distribution is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key. In real world situations, it is often also used with encryption using symmetric key algorithms like the Advanced Encryption Standard algorithm. In the case of QKD this comparison is based on the assumption of perfect single-photon sources and detectors, that cannot be easily implemented.