A (very) brief tour of quantum mechanics, computation, and category
... Einstein, Podolsky, and Rosen (EPR) questioned the completeness of quantum mechanics in the form of a thought experiment involving the measurement of one part of a 2-particle entangled system. According to EPR, two mutually exclusive conclusions may be reached regarding quantum mechanics: either qua ...
... Einstein, Podolsky, and Rosen (EPR) questioned the completeness of quantum mechanics in the form of a thought experiment involving the measurement of one part of a 2-particle entangled system. According to EPR, two mutually exclusive conclusions may be reached regarding quantum mechanics: either qua ...
with x
... velocities) the Newtonian description of mechanics breaks down and the relativistic treatment designed by Einstein must be used. Now, we will see that the description of light in terms of waves breaks down when looking at very small scales. In addition, we will see that objects that we usually ref ...
... velocities) the Newtonian description of mechanics breaks down and the relativistic treatment designed by Einstein must be used. Now, we will see that the description of light in terms of waves breaks down when looking at very small scales. In addition, we will see that objects that we usually ref ...
Quantum nanophotonic phase switch with a single atom.
... changes sign depending on the presence (g . 1) or absence (g 5 0) of a strongly coupled atom. If the atom is prepared in a superposition of internal states, one of which does not couple to the cavity mode (for example another hyperfine atomic sublevel), the phase of the atomic superposition is switc ...
... changes sign depending on the presence (g . 1) or absence (g 5 0) of a strongly coupled atom. If the atom is prepared in a superposition of internal states, one of which does not couple to the cavity mode (for example another hyperfine atomic sublevel), the phase of the atomic superposition is switc ...
Quantum-state estimation
... the suggested algorithm by Smithey et al. @2#. Since that time, many improvements and new techniques have been proposed @3–12#, to cite without requirements for completeness at least some titles from the existing literature @13#. Even if the method comes from optics, similar methods such as quantum ...
... the suggested algorithm by Smithey et al. @2#. Since that time, many improvements and new techniques have been proposed @3–12#, to cite without requirements for completeness at least some titles from the existing literature @13#. Even if the method comes from optics, similar methods such as quantum ...
classical and
... Classical Mechanics should be obtained as a limiting case of a Quantum Mechanics formulation.5 Even though in quantum mechanics there is no such a concept as “the velocity of a particle” in the classical sense, still (as we will see in the coming chapters) the new theory provides a reasonable defini ...
... Classical Mechanics should be obtained as a limiting case of a Quantum Mechanics formulation.5 Even though in quantum mechanics there is no such a concept as “the velocity of a particle” in the classical sense, still (as we will see in the coming chapters) the new theory provides a reasonable defini ...
A maximality result for orthogonal quantum groups
... For G = On , Un , Sn it was later discovered by Wang [19], [20] that one can also obtain compact quantum groups by “removing” the commutation relations entirely. In this way one obtains “free” versions On+ , Un+ , Sn+ of these classical groups. This construction has been axiomatized in [11] in terms ...
... For G = On , Un , Sn it was later discovered by Wang [19], [20] that one can also obtain compact quantum groups by “removing” the commutation relations entirely. In this way one obtains “free” versions On+ , Un+ , Sn+ of these classical groups. This construction has been axiomatized in [11] in terms ...
Nucleus-mediated spin-flip transitions in GaAs quantum dots
... reasons for studying them are that relevant quantum dots are fabricated in such structures and GaAs has peculiar electron and phonon properties which are of interest. There are two main types of gate controlled dots in these systems, so-called vertical and lateral dots.8 They are characterized by di ...
... reasons for studying them are that relevant quantum dots are fabricated in such structures and GaAs has peculiar electron and phonon properties which are of interest. There are two main types of gate controlled dots in these systems, so-called vertical and lateral dots.8 They are characterized by di ...
On the Derivation of the Time-Dependent Equation of Schrodinger
... ``Dreimannerarbeit'' of Born, Heisenberg, and Jordan. (8) It is interesting that at this stage in the development of quantum mechanics it was not known how to quantise fields or even the free motion of particle beams. Hence, in both Refs. 7 and 8 they are considered as external sources perturbing t ...
... ``Dreimannerarbeit'' of Born, Heisenberg, and Jordan. (8) It is interesting that at this stage in the development of quantum mechanics it was not known how to quantise fields or even the free motion of particle beams. Hence, in both Refs. 7 and 8 they are considered as external sources perturbing t ...
Quantum Computer Simulation Using CUDA
... within the same 512-element block of the vector state array. 512 complex numbers is the largest power of two we can fit into shared memory on the GTX280 graphics cards. This observation suggests a means of using shared memory to improve performance. Each block will copy-in 512 elements from the stat ...
... within the same 512-element block of the vector state array. 512 complex numbers is the largest power of two we can fit into shared memory on the GTX280 graphics cards. This observation suggests a means of using shared memory to improve performance. Each block will copy-in 512 elements from the stat ...
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.