Proposal for Implementing Device
... apply them to the case of imperfect devices and how to compute the corresponding key rate. Moving slightly away from a full device-independent scenario, we also consider the case where the end detectors are trusted and can be moved out of the black boxes. This means that the detectors are well chara ...
... apply them to the case of imperfect devices and how to compute the corresponding key rate. Moving slightly away from a full device-independent scenario, we also consider the case where the end detectors are trusted and can be moved out of the black boxes. This means that the detectors are well chara ...
Program - LQG
... We will present a general mechanism for the emergence of an effective classical spacetime from a fundamental theory of quantum cosmology coupled to matter. This idea is based on QFT on quantum spacetime, and the emergent classical metric is not just the naïve expectation value of a ``metric operator ...
... We will present a general mechanism for the emergence of an effective classical spacetime from a fundamental theory of quantum cosmology coupled to matter. This idea is based on QFT on quantum spacetime, and the emergent classical metric is not just the naïve expectation value of a ``metric operator ...
File
... that the more accurately an object’s position can be observed, the less accurately its momentum can. This is because shorter wavelengths of light (use as a sort of measuring-stick) have higher energies, and disrupt a particle’s momentum more strongly. Heisenberg earned the 1932 Nobel Prize in Physic ...
... that the more accurately an object’s position can be observed, the less accurately its momentum can. This is because shorter wavelengths of light (use as a sort of measuring-stick) have higher energies, and disrupt a particle’s momentum more strongly. Heisenberg earned the 1932 Nobel Prize in Physic ...
Annalen der Physik
... Einstein’s fourth miraculous paper Today physicists are doing reruns of old experiments with extraordinary precision testing the constancy of the speed of light. Nature 427, 482 - 484 (2004) Recent claims coming from the two leading candidates for a quantum theory of gravity challenge this basi ...
... Einstein’s fourth miraculous paper Today physicists are doing reruns of old experiments with extraordinary precision testing the constancy of the speed of light. Nature 427, 482 - 484 (2004) Recent claims coming from the two leading candidates for a quantum theory of gravity challenge this basi ...
The Learnability of Quantum States
... unwanted interaction between a QC and its external environment, “prematurely measuring” the quantum state A few skeptics, in CS and physics, even argue that building a QC will be fundamentally impossible I don’t expect them to be right, but I hope they are! If so, it would be a revolution in physics ...
... unwanted interaction between a QC and its external environment, “prematurely measuring” the quantum state A few skeptics, in CS and physics, even argue that building a QC will be fundamentally impossible I don’t expect them to be right, but I hope they are! If so, it would be a revolution in physics ...
Document
... (2) Local operations on H_B does not change the degree of entanglement between Alice and Bob. ...
... (2) Local operations on H_B does not change the degree of entanglement between Alice and Bob. ...
Quantum Communications in the Maritime Environment
... That is, Eve is unable to extract any information from the transmission because she is measuring in the wrong basis, i.e., she cannot properly interpret the sequence of signals sent by Alice to obtain the correct sequence of logical bits comprising the message (“1001010001”). Now suppose Eve thinks ...
... That is, Eve is unable to extract any information from the transmission because she is measuring in the wrong basis, i.e., she cannot properly interpret the sequence of signals sent by Alice to obtain the correct sequence of logical bits comprising the message (“1001010001”). Now suppose Eve thinks ...
What`s the big idea? - Perimeter Institute
... a quantum computer. What’s a quantum computer? A new breed of computer that might make today’s supercomputers look like mere hand calculators. Instead of processing bits of information (binary digits, 0 or 1) they would process qubits of quantum information: quantum superpositions of both 0 and 1—si ...
... a quantum computer. What’s a quantum computer? A new breed of computer that might make today’s supercomputers look like mere hand calculators. Instead of processing bits of information (binary digits, 0 or 1) they would process qubits of quantum information: quantum superpositions of both 0 and 1—si ...
New Type of Einstein-Podolsky-Rosen
... where the n; quantum mechanically describe a state the case in which particle 1 or 2 has spin "up" or "down, respectively, along the direction n. Suppose one sets up his experiment to measure the spin of particle 1 along the x direction, then particle 2 will immediately be found to have its spin ant ...
... where the n; quantum mechanically describe a state the case in which particle 1 or 2 has spin "up" or "down, respectively, along the direction n. Suppose one sets up his experiment to measure the spin of particle 1 along the x direction, then particle 2 will immediately be found to have its spin ant ...
The Learnability of Quantum States
... environment, “prematurely measuring” the quantum state A few skeptics, in CS and physics, even argue that building a QC will be fundamentally impossible I don’t expect them to be right, but I hope they are! If so, it would be a revolution in physics And for me, putting quantum mechanics to the test ...
... environment, “prematurely measuring” the quantum state A few skeptics, in CS and physics, even argue that building a QC will be fundamentally impossible I don’t expect them to be right, but I hope they are! If so, it would be a revolution in physics And for me, putting quantum mechanics to the test ...
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.