Counterfactual Statements and Weak Measurements: an
... or C 2 − N OT gate of quantum computing [13] could be applied for a short time, so that if the two ions are in the ground states, identified with the logical value 1, the third ion undergoes a Rabi oscillation between its states |gi and |ei. Rather than the rotation of π radians corresponding to a ...
... or C 2 − N OT gate of quantum computing [13] could be applied for a short time, so that if the two ions are in the ground states, identified with the logical value 1, the third ion undergoes a Rabi oscillation between its states |gi and |ei. Rather than the rotation of π radians corresponding to a ...
L Generation of squeezed states and twin beams system
... four-wave mixing, these concerns are largely alleviated. Briefly, we predict that very strong squeezing can be achieved at typical powers available experimentally. This is because the optical non-linearity responsible for squeezing is generated by a two-photon transition that couples the two low-lyi ...
... four-wave mixing, these concerns are largely alleviated. Briefly, we predict that very strong squeezing can be achieved at typical powers available experimentally. This is because the optical non-linearity responsible for squeezing is generated by a two-photon transition that couples the two low-lyi ...
Chapter 5
... entirely new topics (e.g., delayed-‐choice experiments) that created additional opportunities for students to explore the sometimes fluid boundaries between scientific interpretation and theory. The entiret ...
... entirely new topics (e.g., delayed-‐choice experiments) that created additional opportunities for students to explore the sometimes fluid boundaries between scientific interpretation and theory. The entiret ...
Quantum Computing - Department of Computing
... Quantum mechanics is a very accurate description of nature as it predicts quantum effects up to an astonishing precision of 14 decimal places. But we do not know why nature works like that and why quantum mechanics gives such a good description of nature. In other words, quantum mechanics tells us h ...
... Quantum mechanics is a very accurate description of nature as it predicts quantum effects up to an astonishing precision of 14 decimal places. But we do not know why nature works like that and why quantum mechanics gives such a good description of nature. In other words, quantum mechanics tells us h ...
Quantum gases in optical lattices
... sation – happens when bosonic atoms are cooled such that Institute for Quantum Optics (MPQ ) in Garching observed their de Broglie wavelength becomes comparable with the such a transition for the first time (see Greiner et al. in further average distance between them. reading). This publication is c ...
... sation – happens when bosonic atoms are cooled such that Institute for Quantum Optics (MPQ ) in Garching observed their de Broglie wavelength becomes comparable with the such a transition for the first time (see Greiner et al. in further average distance between them. reading). This publication is c ...
Information, Q-Bits, and Natural Reference: a bridge from Bit to It to
... aspects of quantum physics and some of the puzzling aspects of organic life and mental phenomena. In the process of articulating these connections between information “bits”, physical its, ecological systems, autopoetic molecules, and phenomenological qualia, I will be agreeing with Lycan that all o ...
... aspects of quantum physics and some of the puzzling aspects of organic life and mental phenomena. In the process of articulating these connections between information “bits”, physical its, ecological systems, autopoetic molecules, and phenomenological qualia, I will be agreeing with Lycan that all o ...
Modeling and Control of Quantum Systems: An Introduction
... experimental work has been developed since the early experimental and theoretical contributions on control of travelingwave quantum fields [22], [23], [24], [25], which were among the first quantum-limited feedback control experiments to be performed. A number of interesting, control oriented result ...
... experimental work has been developed since the early experimental and theoretical contributions on control of travelingwave quantum fields [22], [23], [24], [25], which were among the first quantum-limited feedback control experiments to be performed. A number of interesting, control oriented result ...
The measure of existence of a quantum world and the Sleeping
... of the coin might matter (he distinguished between a ‘random’ coin and a ‘mathematical’ coin, see §7) and since a particular (quantum) implementation of the fair coin is crucial for our analysis, we have to justify Vaidman's move. There is no place for a random variable in classical physics: knowing ...
... of the coin might matter (he distinguished between a ‘random’ coin and a ‘mathematical’ coin, see §7) and since a particular (quantum) implementation of the fair coin is crucial for our analysis, we have to justify Vaidman's move. There is no place for a random variable in classical physics: knowing ...
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... At a physical level, communication in the Multi-SIMD architecture is assumed to be achieved through quantum teleportation (QT), a phenomenon that makes transmission of exact qubit states possible. QT requires a pre-distribution of entangled Einstein-PodolskyRosen (EPR) pairs of qubits between the re ...
... At a physical level, communication in the Multi-SIMD architecture is assumed to be achieved through quantum teleportation (QT), a phenomenon that makes transmission of exact qubit states possible. QT requires a pre-distribution of entangled Einstein-PodolskyRosen (EPR) pairs of qubits between the re ...
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.