quantum-gravity-presentation
... Quantum Gravity: Why so Difficult? • Don’t Buy the Tickets Quite Yet (III) • What Does it Mean to Have an Infinite Series with Terms of Increasing Dimension? • If You “Cutoff” the Series, You Can Apparently Fiddle with the Resulting Equations to Get Something With a Physical Meaning • But You Canno ...
... Quantum Gravity: Why so Difficult? • Don’t Buy the Tickets Quite Yet (III) • What Does it Mean to Have an Infinite Series with Terms of Increasing Dimension? • If You “Cutoff” the Series, You Can Apparently Fiddle with the Resulting Equations to Get Something With a Physical Meaning • But You Canno ...
Quantum Geometry: a reunion of Physics and Math
... Some Poisson spaces look locally like a flat phase space with its Poisson bracket. That is, around every point there are local coordinates Xi and Pi such that ...
... Some Poisson spaces look locally like a flat phase space with its Poisson bracket. That is, around every point there are local coordinates Xi and Pi such that ...
Quantum Physics 2005 Notes-2 The State Function and its Interpretation
... • Every physically realizable state of a system is described in quantum mechanics by a state function # that contains all accessible information about the system in that state. – The phrase “wave function” is usually used to mean a state function that is specified as a function of position and time ...
... • Every physically realizable state of a system is described in quantum mechanics by a state function # that contains all accessible information about the system in that state. – The phrase “wave function” is usually used to mean a state function that is specified as a function of position and time ...
Exploring Quantum Physics with Superconducting Circuits
... • the cavity: a superconducting 1D transmission line resonator with large vacuum field E0 and long photon life time 1/κ • the atom: a superconducting qubit with large dipole moment d and long coherence time 1/γ and fixed position … • … or any microscopic/macroscopic quantum element or ensemble there ...
... • the cavity: a superconducting 1D transmission line resonator with large vacuum field E0 and long photon life time 1/κ • the atom: a superconducting qubit with large dipole moment d and long coherence time 1/γ and fixed position … • … or any microscopic/macroscopic quantum element or ensemble there ...
Full text in PDF form
... their models on known energy functions or operators. Hence they do necessarily not account for the continuous interaction with the environement and the corresponding ‡uctuations of entropy. At the same time they are able to measure energies within arbitrarily short periods of time [1]. Consequently ...
... their models on known energy functions or operators. Hence they do necessarily not account for the continuous interaction with the environement and the corresponding ‡uctuations of entropy. At the same time they are able to measure energies within arbitrarily short periods of time [1]. Consequently ...
A functional quantum programming language
... We can read had as an operation which, depending on its input qubit x, returns one of two superpositions of a qubit. We can also easily calculate that applying had twice gets us back where we started by cancelling out amplitudes. An important feature of quantum programming is the possibility to crea ...
... We can read had as an operation which, depending on its input qubit x, returns one of two superpositions of a qubit. We can also easily calculate that applying had twice gets us back where we started by cancelling out amplitudes. An important feature of quantum programming is the possibility to crea ...
Aalborg Universitet Beyond the Modern Physics and Cosmological Equations
... Zero-point energy, also called quantum vacuum zero-point energy, is the lowest possible energy that a quantum mechanical physical system may have; it is the energy of its ground state. All quantum mechanical systems undergo fluctuations even in their ground state and have an associated zero-point en ...
... Zero-point energy, also called quantum vacuum zero-point energy, is the lowest possible energy that a quantum mechanical physical system may have; it is the energy of its ground state. All quantum mechanical systems undergo fluctuations even in their ground state and have an associated zero-point en ...
National Institute for Theoretical Physics
... 8. I. Snyman and Y.V. Nazarov (2007) Polarization of a charge qubit strongly coupled to a voltage-driven quantum point contact. Phys. Rev. Lett. 99, 096802. 9. J. Tworzydło, I. Snyman, A.R. Akhmerov and C.J.W. Beenakker (2007) Valley-isospin dependence of the quantum Hall effect in a graphene p-n ju ...
... 8. I. Snyman and Y.V. Nazarov (2007) Polarization of a charge qubit strongly coupled to a voltage-driven quantum point contact. Phys. Rev. Lett. 99, 096802. 9. J. Tworzydło, I. Snyman, A.R. Akhmerov and C.J.W. Beenakker (2007) Valley-isospin dependence of the quantum Hall effect in a graphene p-n ju ...
The Power of Quantum Advice
... Idea: Take some advice resource (such as a coin or a quantum state), and simulate it using a short classical string, together with a polynomial number of untrusted advice resources. In other words, all the relevant information in the advice resource gets packed into an ordinary string (which we say ...
... Idea: Take some advice resource (such as a coin or a quantum state), and simulate it using a short classical string, together with a polynomial number of untrusted advice resources. In other words, all the relevant information in the advice resource gets packed into an ordinary string (which we say ...
PPT - Fernando Brandao
... Larger Speed-ups with “quantum input” Result 3: There is a quantum algorithm for solving SDPs running in time m1/2poly(log(n, m), s, R, r, δ, rank) with data in quantum form Quantum Oracle Model: There is an oracle that given i, outputs the eigenvalues of Ai and its eigenvectors as quantum states r ...
... Larger Speed-ups with “quantum input” Result 3: There is a quantum algorithm for solving SDPs running in time m1/2poly(log(n, m), s, R, r, δ, rank) with data in quantum form Quantum Oracle Model: There is an oracle that given i, outputs the eigenvalues of Ai and its eigenvectors as quantum states r ...
Wilson-Sommerfeld quantization rule revisited
... show how far (28) is satisfied even in the small-n regime. The kinetic part of the Hamiltonian is of the same form as (19), but the potential is different for the various cases as shown in the table. One happily notes that near-exact calculational data exhibit a rapid approach to the WSQR result in ...
... show how far (28) is satisfied even in the small-n regime. The kinetic part of the Hamiltonian is of the same form as (19), but the potential is different for the various cases as shown in the table. One happily notes that near-exact calculational data exhibit a rapid approach to the WSQR result in ...
Polaronic states in II–VI quantum dot
... states, only with different effective mass (which for a hole is no longer isotropic) and potential discontinuity at the interface. In the other hand, we consider small quantum dots, i.e. the strong confinement regime, which leads to well-separated electron and hole levels within the dot. This allows ...
... states, only with different effective mass (which for a hole is no longer isotropic) and potential discontinuity at the interface. In the other hand, we consider small quantum dots, i.e. the strong confinement regime, which leads to well-separated electron and hole levels within the dot. This allows ...
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.