Annual Report 2003-2004 The Institute for Quantum Engineering, Science, and Technology
... through a semiconductor superlattice (alternating layers of semiconducting material with different affinities for electrons), amplification of THz radiation, or “gain,” should be possible under special conditions. However, the evidence for gain came from interpretation of features in a plot of curre ...
... through a semiconductor superlattice (alternating layers of semiconducting material with different affinities for electrons), amplification of THz radiation, or “gain,” should be possible under special conditions. However, the evidence for gain came from interpretation of features in a plot of curre ...
Experiment and the foundations of quantum physics
... is suggested if, as in our example in Sec. II, we consider determining the path a particle takes through the double-slit assembly by scattering some other particle from it. That this is too limited a view is brought out by the experiment discussed in the preceding section. The absence of the interfe ...
... is suggested if, as in our example in Sec. II, we consider determining the path a particle takes through the double-slit assembly by scattering some other particle from it. That this is too limited a view is brought out by the experiment discussed in the preceding section. The absence of the interfe ...
sch4u-quantumtheory
... •Photoelectric Effect (discovered by Heinrich Hertz; 1887) = the release of electrons from a metal surface when struck by light of “appropriate” frequency •According to classical theory, the intensity of the light shone on the metal impacts the KE of the liberated electrons; the photoelectric effect ...
... •Photoelectric Effect (discovered by Heinrich Hertz; 1887) = the release of electrons from a metal surface when struck by light of “appropriate” frequency •According to classical theory, the intensity of the light shone on the metal impacts the KE of the liberated electrons; the photoelectric effect ...
File
... “As in my conversations with my brother we always arrived at the conclusion that in the case of X-rays one had both waves and corpuscles, thus suddenly - ... it was certain in the course of summer 1923 - I got the idea that one had to extend this duality to material particles, especially to electron ...
... “As in my conversations with my brother we always arrived at the conclusion that in the case of X-rays one had both waves and corpuscles, thus suddenly - ... it was certain in the course of summer 1923 - I got the idea that one had to extend this duality to material particles, especially to electron ...
Memory-built-in quantum teleportation with photonic and atomic qubits
... easily transmitted over large distances. Second, different from a continuous-variable system, its teleportation fidelity is insensitive to photon losses. In practice, an overall transmission attenuation of 10−4 is tolerable with current technology, as demonstrated in recent experiments21,22 . Moreov ...
... easily transmitted over large distances. Second, different from a continuous-variable system, its teleportation fidelity is insensitive to photon losses. In practice, an overall transmission attenuation of 10−4 is tolerable with current technology, as demonstrated in recent experiments21,22 . Moreov ...
The physics of density matrices (Robert Helling — )
... As a last remark of this general introductory section, I would like to point out that there is an approach to quantum theory where one starts out without an a priori Hilbert space but with just an abstract (C*) algebra of observables (defined in terms of their commutation relations). In that approa ...
... As a last remark of this general introductory section, I would like to point out that there is an approach to quantum theory where one starts out without an a priori Hilbert space but with just an abstract (C*) algebra of observables (defined in terms of their commutation relations). In that approa ...
The D-Wave Quantum Computer - D
... A quantum computer taps directly into the fundamental fabric of reality – the strange and counter-intuitive world of quantum mechanics – to speed computation. Rather than store information as 0s or 1s as conventional computers do, a quantum computer uses qubits – which can be 1 or 0 or both at the s ...
... A quantum computer taps directly into the fundamental fabric of reality – the strange and counter-intuitive world of quantum mechanics – to speed computation. Rather than store information as 0s or 1s as conventional computers do, a quantum computer uses qubits – which can be 1 or 0 or both at the s ...
Chapter 08
... convert plaintext to ciphertext The level of complexity of an algorithm can be increased by using a key, a code necessary to encrypt or decrypt a message correctly using the algorithm Knowing the algorithm (the cipher) should not enable readability; good security assumes an eavesdropper knows the ci ...
... convert plaintext to ciphertext The level of complexity of an algorithm can be increased by using a key, a code necessary to encrypt or decrypt a message correctly using the algorithm Knowing the algorithm (the cipher) should not enable readability; good security assumes an eavesdropper knows the ci ...
Geometry, Integrability
... adiabatic cyclic evolution of non-degenerates eigenstates of quantum Hermitian Hamiltonian. Later, the growing investigations were devoted to the generalization of Berry’s result to several contexts. Indeed, Wilzek and Zee [13] extend this result to adiabatic evolution of degenerates eigenstates. Re ...
... adiabatic cyclic evolution of non-degenerates eigenstates of quantum Hermitian Hamiltonian. Later, the growing investigations were devoted to the generalization of Berry’s result to several contexts. Indeed, Wilzek and Zee [13] extend this result to adiabatic evolution of degenerates eigenstates. Re ...
Is Qi the same as Energy?
... [Q2] who suggests that the harmonisation of the organism generated by meridian work is produced through a phenomenon called Quantum Coherence. Quantum Coherence is a state of connection between certain types of quantum entities called bosons so that they are all ‘in phase’; profoundly connected in a ...
... [Q2] who suggests that the harmonisation of the organism generated by meridian work is produced through a phenomenon called Quantum Coherence. Quantum Coherence is a state of connection between certain types of quantum entities called bosons so that they are all ‘in phase’; profoundly connected in a ...
Do Global Virtual Axionic Gravitons Exist?
... Nevertheless, looking from the present-day theoretical point of view, the model reasoning presented in this paper allows to make use of the hypothetically existing virtual axionic particle-like global gravitons in order to search, ...
... Nevertheless, looking from the present-day theoretical point of view, the model reasoning presented in this paper allows to make use of the hypothetically existing virtual axionic particle-like global gravitons in order to search, ...
4.quantumorbitals
... Orbitals are areas in 3D space where the electrons most probably are. The energy of the electron is in its vibrational modes- like notes on a guitar string. Photons are produced when high energy modes change to lower energy modes ...
... Orbitals are areas in 3D space where the electrons most probably are. The energy of the electron is in its vibrational modes- like notes on a guitar string. Photons are produced when high energy modes change to lower energy modes ...
Universal Quantum Computation with the Exchange Interaction
... whether the spins 1 and 2 of the block are in a singlet or a triplet suffices to perfectly distinguish [7] |0L i from |1L i (again, the state of the third spin does not enter). Thus, for example, the AC capacitance scheme for spin measurement proposed by Kane [3] is directly applicable to the coded- ...
... whether the spins 1 and 2 of the block are in a singlet or a triplet suffices to perfectly distinguish [7] |0L i from |1L i (again, the state of the third spin does not enter). Thus, for example, the AC capacitance scheme for spin measurement proposed by Kane [3] is directly applicable to the coded- ...
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.