Quantum error correction
... Quantum analogue to a bit is a qubit. Qubit is a two-dimensional quantum system whose eigenstates are commonly denoted as |0i and |1i. Unlike bits, which can be only in two states, qubits can exist in coherent superposition of states |0i and |1i [3]. An arbitrary state of a qubit can be expressed as ...
... Quantum analogue to a bit is a qubit. Qubit is a two-dimensional quantum system whose eigenstates are commonly denoted as |0i and |1i. Unlike bits, which can be only in two states, qubits can exist in coherent superposition of states |0i and |1i [3]. An arbitrary state of a qubit can be expressed as ...
ןב תטיסרבינוא - בגנב ןוירוג
... two-state probability. When the interaction is weak ( V01 << hω 0 , or Ω << ω 0 ) the oscillation amplitude is small, and its frequency is close to ω 0 . When the interaction is strong ( Ω >> ω 0 ) the entire population moves periodically between each of the two states, and its oscillation frequency ...
... two-state probability. When the interaction is weak ( V01 << hω 0 , or Ω << ω 0 ) the oscillation amplitude is small, and its frequency is close to ω 0 . When the interaction is strong ( Ω >> ω 0 ) the entire population moves periodically between each of the two states, and its oscillation frequency ...
Mechanical Proof of the Second Law of Thermodynamics Based on
... is switched off. We assume that at some time tf ≥ tof f any transient effect will be vanished and the system attains a new equilibrium state described by ∂ρ some ρf , such that ∂tf = 0. Thus, before time ti and after tf , the system is at equilibrium, and for ti < t < tf it is out of equilibrium. Du ...
... is switched off. We assume that at some time tf ≥ tof f any transient effect will be vanished and the system attains a new equilibrium state described by ∂ρ some ρf , such that ∂tf = 0. Thus, before time ti and after tf , the system is at equilibrium, and for ti < t < tf it is out of equilibrium. Du ...
here.
... • To estimate this life time, we need to know the rates for spontaneous emission Ru→l . To find this rate we could apply first order time-dependent perturbation theory as in the case of stimulated emission/absorption. However, to do so, we will need to know the electromagnetic field in the vacuum, w ...
... • To estimate this life time, we need to know the rates for spontaneous emission Ru→l . To find this rate we could apply first order time-dependent perturbation theory as in the case of stimulated emission/absorption. However, to do so, we will need to know the electromagnetic field in the vacuum, w ...
INSTITUTE OF NUCLEAR PHYSICS
... well known from the wave optics. Many semiclassical models, based on parameterization of the elastic scattering amplitude or of the elastic scattering matrix elements, were used to describe these patterns successfully. The present paper presents how these patterns can be treated in the pure quantum ...
... well known from the wave optics. Many semiclassical models, based on parameterization of the elastic scattering amplitude or of the elastic scattering matrix elements, were used to describe these patterns successfully. The present paper presents how these patterns can be treated in the pure quantum ...
Quantum Computer - Physics, Computer Science and Engineering
... P. Shor (AT&T) was wanting to demonstrate that a quantum computer could be used to solve a real problem, as opposed to the contrived problems demonstrated up to that time (mid 1990s). Shor: if you can relate the (real) problem of finding the factors of a large composite integer to that of finding th ...
... P. Shor (AT&T) was wanting to demonstrate that a quantum computer could be used to solve a real problem, as opposed to the contrived problems demonstrated up to that time (mid 1990s). Shor: if you can relate the (real) problem of finding the factors of a large composite integer to that of finding th ...
A note on the realignment criterion
... but f` (s1 , . . . , sm2 ) > B` (m, n). Therefore, the bound B` (m, n) can be used to detect entanglement for which the realignment criterion fails. Numerical estimations for these bounds were given for (m, n) = (2, 2) and (2, 3) in [10]. The numerical results also suggest that B̃` (2, 2) = B` (2, 2 ...
... but f` (s1 , . . . , sm2 ) > B` (m, n). Therefore, the bound B` (m, n) can be used to detect entanglement for which the realignment criterion fails. Numerical estimations for these bounds were given for (m, n) = (2, 2) and (2, 3) in [10]. The numerical results also suggest that B̃` (2, 2) = B` (2, 2 ...
Document
... QKD using spatial entanglement Mutual information analysis • Since the Hilbert space of the photonic degree of freedom is large, we can expect to transmit more than one bit per photon • For actual PDC sources, the mutual information per photon pair is determined by the length of the crystal Lz and ...
... QKD using spatial entanglement Mutual information analysis • Since the Hilbert space of the photonic degree of freedom is large, we can expect to transmit more than one bit per photon • For actual PDC sources, the mutual information per photon pair is determined by the length of the crystal Lz and ...
Quantum Symmetric States - UCLA Department of Mathematics
... To investigate QSS(A) as a compact, convex subset of S(A), to characterize its extreme points and to study certain convex subsets: • the tracial quantum symmetric states TQSS(A) = QSS(A) ∩ T S(A) • the central quantum symmetric states ZQSS(A) = {ψ ∈ QSS(A) | Tψ ⊆ Z(Mψ )} • the tracial central quantu ...
... To investigate QSS(A) as a compact, convex subset of S(A), to characterize its extreme points and to study certain convex subsets: • the tracial quantum symmetric states TQSS(A) = QSS(A) ∩ T S(A) • the central quantum symmetric states ZQSS(A) = {ψ ∈ QSS(A) | Tψ ⊆ Z(Mψ )} • the tracial central quantu ...
The Quantum Circuit Model and Universal Quantum Computation
... into which symbols from some alphabet can be written and erased. Usually cells that have not been written on are assumed to be filled with no symbol. The second component of the Turing machine is a head. This is a device for reading and writing symbols onto the tape. This head will occupy only one c ...
... into which symbols from some alphabet can be written and erased. Usually cells that have not been written on are assumed to be filled with no symbol. The second component of the Turing machine is a head. This is a device for reading and writing symbols onto the tape. This head will occupy only one c ...
Probability amplitude
In quantum mechanics, a probability amplitude is a complex number used in describing the behaviour of systems. The modulus squared of this quantity represents a probability or probability density.Probability amplitudes provide a relationship between the wave function (or, more generally, of a quantum state vector) of a system and the results of observations of that system, a link first proposed by Max Born. Interpretation of values of a wave function as the probability amplitude is a pillar of the Copenhagen interpretation of quantum mechanics. In fact, the properties of the space of wave functions were being used to make physical predictions (such as emissions from atoms being at certain discrete energies) before any physical interpretation of a particular function was offered. Born was awarded half of the 1954 Nobel Prize in Physics for this understanding (see #References), and the probability thus calculated is sometimes called the ""Born probability"". These probabilistic concepts, namely the probability density and quantum measurements, were vigorously contested at the time by the original physicists working on the theory, such as Schrödinger and Einstein. It is the source of the mysterious consequences and philosophical difficulties in the interpretations of quantum mechanics—topics that continue to be debated even today.