Quantum coherence, evolution of the Wigner function, and transition from quantum to classical dynamics for a chaotic system

1996 ◽  
Vol 6 (4) ◽  
pp. 534-542 ◽  
Author(s):  
Andrey R. Kolovsky
Keyword(s):  
Wigner Function ◽  
Chaotic System ◽  
Quantum Coherence ◽  
Classical Dynamics

scholarly journals Investigating quantum coherence from discrete Wigner function

2017 ◽  
Vol 66 (11) ◽  
pp. 110301
Author(s):  
Lin Yin ◽  
Huang Ming-Da ◽  
Yu Ya-Fei ◽  
Zhang Zhi-Ming
Keyword(s):  
Wigner Function ◽  
Quantum Coherence ◽  
Discrete Wigner Function

Engineering Electronic Structure to Protect Phase Memory in Molecular Qubits by Minimising Orbital Angular Momentum

2018 ◽  
Author(s):  
Ana Maria Ariciu ◽  
David H. Woen ◽  
Daniel N. Huh ◽  
Lydia Nodaraki ◽  
Andreas Kostopoulos ◽  
...  
Keyword(s):  
Electron Spin ◽  
Quantum Coherence ◽  
Quantum Information Processing ◽  
Pulse Sequences ◽  
Grover Algorithm ◽  
Ligand Shell ◽  
Information Strategies ◽  
Spin Qubit ◽  
Molecular Spin ◽  
The Impact

Using electron spins within molecules for quantum information processing (QIP) was first proposed by Leuenberger and Loss (1), who showed how the Grover algorithm could be mapped onto a Mn12 cage (2). Since then several groups have examined two-level (S = ½) molecular spin systems as possible qubits (3-12). There has also been a report of the implementation of the Grover algorithm in a four-level molecular qudit (13). A major challenge is to protect the spin qubit from noise that causes loss of phase information; strategies to minimize the impact of noise on qubits can be categorized as corrective, reductive, or protective. Corrective approaches allow noise and correct for its impact on the qubit using advanced microwave pulse sequences (3). Reductive approaches reduce the noise by minimising the number of nearby nuclear spins (7-11), and increasing the rigidity of molecules to minimise the effect of vibrations (which can cause a fluctuating magnetic field via spin-orbit coupling) (9,11); this is essentially engineering the ligand shell surrounding the electron spin. A protective approach would seek to make the qubit less sensitive to noise: an example of the protective approach is the use of clock transitions to render spin states immune to magnetic fields at first order (12). Here we present a further protective method that would complement reductive and corrective approaches to enhancing quantum coherence in molecular qubits. The target is a molecular spin qubit with an effective 2S ground state: we achieve this with a family of divalent rare-earth molecules that have negligible magnetic anisotropy such that the isotropic nature of the electron spin renders the qubit markedly less sensitive to magnetic noise, allowing coherent spin manipulations even at room temperature. If combined with the other strategies, we believe this could lead to molecular qubits with substantial advantages over competing qubit proposals.<br>

The inner bound of quantum spacetime

2019 ◽  
Author(s):  
Matheus Pereira Lobo
Keyword(s):  
Wigner Function ◽  
Uncertainty Principle ◽  
Quantum Spacetime

This article addresses the connection of the UNCERTAINTY PRINCIPLE with the WIGNER FUNCTION.

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