Mechanical Proof of the Second Law of Thermodynamics Based on
... This is also known as the Helmholtz Entropy (Campisi, 2005). Quantization of the Helmholtz Entropy is almost immediate. Indeed, using a colorful expression, I would say that Eq. (4) invites the reader to quantize. Using the semiclassical approximation of Bohr-Sommerfeld (Landau and Lifshitz, 1958) a ...
... This is also known as the Helmholtz Entropy (Campisi, 2005). Quantization of the Helmholtz Entropy is almost immediate. Indeed, using a colorful expression, I would say that Eq. (4) invites the reader to quantize. Using the semiclassical approximation of Bohr-Sommerfeld (Landau and Lifshitz, 1958) a ...
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... it a better candidate for practical atom interferometry for rotation sensing. Furthermore, the CI may be used to realize novel configuration where the wavepackets may trace out multiple loops in a manner such that the rotational sensitivity would vanish, thus making it more versatile for other measu ...
... it a better candidate for practical atom interferometry for rotation sensing. Furthermore, the CI may be used to realize novel configuration where the wavepackets may trace out multiple loops in a manner such that the rotational sensitivity would vanish, thus making it more versatile for other measu ...
Reflections on the deBroglie–Bohm Quantum Potential
... Theory came about (in part) from the abandonment of those previously held physical concepts and principles mentioned above. The state of a quantum system is represented in Orthodox Quantum Theory by a (state) vector in an abstract, mathematical space. The state vector is assumed to contain all possi ...
... Theory came about (in part) from the abandonment of those previously held physical concepts and principles mentioned above. The state of a quantum system is represented in Orthodox Quantum Theory by a (state) vector in an abstract, mathematical space. The state vector is assumed to contain all possi ...
Superconducting Circuits and Quantum Computation—T. P. Orlando
... Chapter 20. Superconducting Circuits and Quantum Computation Figure 1a shows a SEM image of the persistent current qubit (inner loop) and the measuring dc SQUID (outer) loop. A schematic of the qubit and the measuring circuit is shown in Figure 1b, where the Josephson junctions are denoted by x's. ...
... Chapter 20. Superconducting Circuits and Quantum Computation Figure 1a shows a SEM image of the persistent current qubit (inner loop) and the measuring dc SQUID (outer) loop. A schematic of the qubit and the measuring circuit is shown in Figure 1b, where the Josephson junctions are denoted by x's. ...
Steady-state entanglement of two atoms created by classical driving
... systems. It is well known that two-level atoms can be successfully used to model entangled states of qubits as well as realization of different quantum communication protocols. In fact, two-level atoms have been used for decades as the main tool for testing fundamentals of quantum mechanics 共see Ref ...
... systems. It is well known that two-level atoms can be successfully used to model entangled states of qubits as well as realization of different quantum communication protocols. In fact, two-level atoms have been used for decades as the main tool for testing fundamentals of quantum mechanics 共see Ref ...
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.