Topological phase in the de Hass–van Alphen effect induced by the non-local quantum interference

2004 ◽  
Vol 331 (3-4) ◽  
pp. 269-275
Author(s):  
De-Hone Lin
Keyword(s):  
Quantum Interference ◽  
Topological Phase ◽  
Local Quantum ◽  
Non Local

scholarly journals Local and Non-Local Invasive Measurements on Two Quantum Spins Coupled via Nanomechanical Oscillations

Symmetry ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1078
Author(s):  
Dimitrios Maroulakos ◽  
Levan Chotorlishvili ◽  
Dominik Schulz ◽  
Jamal Berakdar
Keyword(s):  
Quantum Coherence ◽  
Indirect Measurement ◽  
Quantum Spin ◽  
Quantum States ◽  
Spin Interaction ◽  
First Case ◽  
Composite Quantum System ◽  
Local Quantum ◽  
Non Local ◽  
Quantum Spins

Symmetry plays the central role in the structure of quantum states of bipartite (or many-body) fermionic systems. Typically, symmetry leads to the phenomenon of quantum coherence and correlations (entanglement) inherent to quantum systems only. In the present work, we study the role of symmetry (i.e., quantum correlations) in invasive quantum measurements. We consider the influence of a direct or indirect measurement process on a composite quantum system. We derive explicit analytical expressions for the case of two quantum spins positioned on both sides of the quantum cantilever. The spins are coupled indirectly to each others via their interaction with a magnetic tip deposited on the cantilever. Two types of quantum witnesses can be considered, which quantify the invasiveness of a measurement on the systems’ quantum states: (i) A local quantum witness stands for the consequence on the quantum spin states of a measurement done on the cantilever, meaning we first perform a measurement on the cantilever, and subsequently a measurement on a spin. (ii) The non-local quantum witness signifies the response of one spin if a measurement is done on the other spin. In both cases the disturbance must involve the cantilever. However, in the first case, the spin-cantilever interaction is linear in the coupling constant Ω , where as in the second case, the spin-spin interaction is quadratic in Ω . For both cases, we find and discuss analytical results for the witness.

scholarly journals Renormalization and conformal invariance of non-local quantum electrodynamics

2020 ◽  
Vol 2020 (8) ◽  
Author(s):  
Matthew Heydeman ◽  
Christian B. Jepsen ◽  
Ziming Ji ◽  
Amos Yarom
Keyword(s):  
Conformal Invariance ◽  
Quantum Electrodynamics ◽  
Local Quantum ◽  
Non Local

IMPLEMENTATION OF NON-LOCAL CNOT WITH MULTIPLE TARGETS OPERATION BY GHZ STATE AND ENTANGLED PURIFICATION

2004 ◽  
Vol 18 (20n21) ◽  
pp. 2953-2961 ◽  
Author(s):  
LIBING CHEN ◽  
HONG LU ◽  
WEICHENG CHEN
Keyword(s):  
Quantum Channel ◽  
Ghz State ◽  
Successful Implementation ◽  
Multiple Targets ◽  
Ghz States ◽  
Physical Resources ◽  
Local Quantum ◽  
Non Local ◽  
Purification Protocol ◽  
Unit Probability

We show how a non-local quantum CNOT with (N-1)-target operation can be implemented with unit fidelity and unit probability by using a N-qubit maximally entangled GHZ state as quantum channel. We also put forward two schemes for probabilistic implementing the operation with unit fidelity by employing a partially entangled pure GHZ state as quantum channel. The overall physical resources required for accomplishing these schemes are different, and the successful implementation probabilities are also different. We also point out the non-local CNOT with (N-1)-target operation can be used as a purification protocol to concentrate entanglement from an ensemble of partially entangled GHZ states into a subensemble of maximally entangled ones.

scholarly journals A Three-Dimensional Non-Local Quantum Vacuum as the Origin of Photons

2020 ◽  
Vol 65 (2) ◽  
pp. 106
Author(s):  
D. Fiscaletti ◽  
A. Sorli
Keyword(s):  
Ground State ◽  
Three Dimensional ◽  
Black Body ◽  
Physical Reality ◽  
Density Fluctuations ◽  
Quantum Vacuum ◽  
Local Quantum ◽  
Non Local ◽  
Planck’S Law ◽  
Quantization Volume

A model of a three-dimensional quantum vacuum defined by the processes of creation/annihilation of quanta corresponding to elementary energy density fluctuations is proposed. In it, a photon is not a primary physical reality but emerges itself as a special state of the three-dimensional quantum vacuum. In this model, the three-dimensional quantum vacuum has a ground state which acts as a “cosmic reservoir” of photons, which emits and absorbs photons and Planck’s law of the spectral distribution of the energy radiated by a black body derives from the fundamental processes in the three-dimensional quantum vacuum, in particular, in the context of a quantization volume responsible for the appearance of photons. Finally, the idea of the Lamb shift of hydrogenoid atoms as a phenomenon determined by the ground state of the quantum vacuum which acts as a reservoir of photons is explored.

scholarly journals Asymptotic Performance of Port-Based Teleportation

2020 ◽  
Author(s):  
Matthias Christandl ◽  
Felix Leditzky ◽  
Christian Majenz ◽  
Graeme Smith ◽  
Florian Speelman ◽  
...  
Keyword(s):  
Matrix Theory ◽  
Building Blocks ◽  
Convergence Result ◽  
Dirichlet Eigenvalue ◽  
Shannon Theory ◽  
Optimal Protocol ◽  
Local Quantum ◽  
Non Local ◽  
Fixed Input ◽  
Quantum Shannon Theory

AbstractQuantum teleportation is one of the fundamental building blocks of quantum Shannon theory. While ordinary teleportation is simple and efficient, port-based teleportation (PBT) enables applications such as universal programmable quantum processors, instantaneous non-local quantum computation and attacks on position-based quantum cryptography. In this work, we determine the fundamental limit on the performance of PBT: for arbitrary fixed input dimension and a large number N of ports, the error of the optimal protocol is proportional to the inverse square of N. We prove this by deriving an achievability bound, obtained by relating the corresponding optimization problem to the lowest Dirichlet eigenvalue of the Laplacian on the ordered simplex. We also give an improved converse bound of matching order in the number of ports. In addition, we determine the leading-order asymptotics of PBT variants defined in terms of maximally entangled resource states. The proofs of these results rely on connecting recently-derived representation-theoretic formulas to random matrix theory. Along the way, we refine a convergence result for the fluctuations of the Schur–Weyl distribution by Johansson, which might be of independent interest.

The accelerated Gisin state: its non-locality, quantum correlations and efficiency to perform quantum masking

2021 ◽  
Vol 21 (15&16) ◽  
pp. 1274-1295
Author(s):  
A.G. Abdelwahab ◽  
A. Ghwail ◽  
N. Metwally ◽  
M.H. Mahran ◽  
A. -S. F. Obada
Keyword(s):  
Quantum Correlations ◽  
Local Behavior ◽  
Quantum Uncertainty ◽  
Acceleration Parameter ◽  
Masking Condition ◽  
Local Quantum Uncertainty ◽  
Local Quantum ◽  
Non Local ◽  
Classical Correlations ◽  
Non Locality

The local and non local behavior of the accelerated Gisin state are investigated either before or after filtering process. It is shown that, the possibility of predicting the non-local behavior is forseen at large values of the weight of the Gisin and acceleration parameters. Due to the filtering process, the non-locality behavior of the Gisin state is predicted at small values of the weight parameter. The amount of non classical correlations are quantified by means of the local quantum uncertainty (LQU)and the concurrence, where the LQU is more sensitive to the non-locality than the concurrence. The phenomenon of the sudden changes is displayed for both quantifiers. Our results show that, the accelerated Gisin state could be used to mask information, where all the possible partitions of the masked state satisfy the masking criteria. Moreover, there is a set of states, which satisfy the masking condition, that is generated between each qubit and its masker qubit. For this set, the amount of the non-classical correlations increases as the acceleration parameter increases . Further, the filtering process improves these correlations, where their maximum bounds are much larger than those depicted for non-filtered states.

Sign in / Sign up

Export Citation Format

Share Document