Lecture 4: Some Properties of Qubits Introduction A Brief Recap
... • But if (say) a0 = 0, then also lose term in |00i ...
... • But if (say) a0 = 0, then also lose term in |00i ...
“Formal” vs. “Empirical” Approaches to Quantum
... intended simply to highlight an interesting formal correspondence between the mathematical frameworks of quantum and classical mechanics or is intended to have some deeper physical signifcance. In its claim that classical mechanics has been shown to be “contained in” Schrodinger’s wave mechanics, su ...
... intended simply to highlight an interesting formal correspondence between the mathematical frameworks of quantum and classical mechanics or is intended to have some deeper physical signifcance. In its claim that classical mechanics has been shown to be “contained in” Schrodinger’s wave mechanics, su ...
Probing exciton localization in nonpolar GaN/AlN quantum dots by
... where the phonons couple efficiently with the confined exciton. It is then possible to calculate the spectral shape function by the combination of every simultaneous emission probability 兿1⬍i⬍50Wqpi for every set of p j. We, however, checked that j in the temperature range that we consider here 共⬍20 ...
... where the phonons couple efficiently with the confined exciton. It is then possible to calculate the spectral shape function by the combination of every simultaneous emission probability 兿1⬍i⬍50Wqpi for every set of p j. We, however, checked that j in the temperature range that we consider here 共⬍20 ...
localization of light - University of Toronto Physics
... photonic band gap." Such microstructures consist of periodic arrays of high-dielectric spheres or cylinders with diameters and lattice constants comparable to the wavelength of light. Figure 1 shows one such microstructure in which a complete bandgap for microwave radiation has been observed. Strict ...
... photonic band gap." Such microstructures consist of periodic arrays of high-dielectric spheres or cylinders with diameters and lattice constants comparable to the wavelength of light. Figure 1 shows one such microstructure in which a complete bandgap for microwave radiation has been observed. Strict ...
Photoemission studies of quantum well states in thin films
... The ®rst photoemission observation of quantum size effects was reported in 1986 [18]. The evidence was clear but the quantum well peaks were very broad, again due to ®lm roughness. Later work, however, clearly established the importance of quantum size effects in ®lms [19±25]. The argument that phot ...
... The ®rst photoemission observation of quantum size effects was reported in 1986 [18]. The evidence was clear but the quantum well peaks were very broad, again due to ®lm roughness. Later work, however, clearly established the importance of quantum size effects in ®lms [19±25]. The argument that phot ...
generalized numerical ranges and quantum error correction
... on a Hilbert space H, which may be infinite dimensional. One can extend the definition of Λk ( A) to A ∈ B(H). If H is infinite dimensional, one may allow k = ∞ by letting Pk be the set of infinite rank orthogonal projections in B(H) in the definition; see [14, 16]. There are a number of reasons to ...
... on a Hilbert space H, which may be infinite dimensional. One can extend the definition of Λk ( A) to A ∈ B(H). If H is infinite dimensional, one may allow k = ∞ by letting Pk be the set of infinite rank orthogonal projections in B(H) in the definition; see [14, 16]. There are a number of reasons to ...
Pdf
... Model I has the advantage that the fully quantum problem is solvable in terms of independent normal modes ~see Appendix!. This is used when examining the system time evolution. First, the trivial time evolution in the normal modes basis set is calculated and then transformed into the BO basis set to ...
... Model I has the advantage that the fully quantum problem is solvable in terms of independent normal modes ~see Appendix!. This is used when examining the system time evolution. First, the trivial time evolution in the normal modes basis set is calculated and then transformed into the BO basis set to ...
Phys. Rev. Lett. 107, 250501 - APS Link Manager
... (2 times the SNL) as shown by the cyan lines. When the resource squeezing is finite, the output states are degraded by excess noise. We show as a reference the theoretical prediction for a vacuum resource [r ¼ 0 in Eq. (3)] by green lines, where the variances of x^ and x^ are 4.8 dB above the SN ...
... (2 times the SNL) as shown by the cyan lines. When the resource squeezing is finite, the output states are degraded by excess noise. We show as a reference the theoretical prediction for a vacuum resource [r ¼ 0 in Eq. (3)] by green lines, where the variances of x^ and x^ are 4.8 dB above the SN ...
Scaling of geometric phase close to multicritical points in cluster
... Here, we study a specific many-body system that can display exotic orders by exploiting Berry phase and winding numbers [14–16]. We focus on a one dimensional spin system whose ground state can be tuned to be an ordered state with local order parameter or to be a state with an exotic order of topolo ...
... Here, we study a specific many-body system that can display exotic orders by exploiting Berry phase and winding numbers [14–16]. We focus on a one dimensional spin system whose ground state can be tuned to be an ordered state with local order parameter or to be a state with an exotic order of topolo ...
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.