scholarly journals Protocol for optically pumping AlH+ to a pure quantum state

2020 ◽  
Vol 22 (42) ◽  
pp. 24423-24430
Author(s):  
Panpan Huang ◽  
Schuyler Kain ◽  
Antonio G. S. de Oliveira-Filho ◽  
Brian C. Odom
Keyword(s):  
Quantum State ◽  
Laser Fields ◽  
Pure Quantum State ◽  
Hyperfine State

Three laser fields drive the population of AlH+ to a single hyperfine state.

On the classical character of control fields in quantum information processing

2002 ◽  
Vol 2 (1) ◽  
pp. 1-13
Author(s):  
S.J. van Enk ◽  
H.J. Kimble
Keyword(s):  
Quantum Computing ◽  
Information Processing ◽  
Quantum Information ◽  
Laser Beam ◽  
Quantum State ◽  
Quantum Communication ◽  
Quantum Information Processing ◽  
Laser Fields ◽  
Undesirable Property

Control fields in quantum information processing are almost by definition assumed to be classical. In reality, however, when such a field is used to manipulate the quantum state of qubits, the qubits always become slightly entangled with the field. For quantum information processing this is an undesirable property, as it precludes perfect quantum computing and quantum communication. Here we consider the interaction of atomic qubits with laser fields and quantify atom-field entanglement in various cases of interest. We find that the entanglement decreases with the average number of photons \bar{n} in a laser beam as $E\propto\log_2 \bar{n}/\bar{n}$ for $\bar{n}\rightarrow\infty$.

scholarly journals Canonical Thermal Pure Quantum State

2013 ◽  
Vol 111 (1) ◽  
Author(s):  
Sho Sugiura ◽  
Akira Shimizu
Keyword(s):  
Quantum State ◽  
Pure Quantum State

Obtainment of thermal noise from a pure quantum state

1987 ◽  
Vol 36 (7) ◽  
pp. 3464-3466 ◽  
Author(s):  
B. Yurke ◽  
M. Potasek
Keyword(s):  
Quantum State ◽  
Thermal Noise ◽  
Pure Quantum State

Uncertainty Relation: From Inequality to Equality

1997 ◽  
Vol 52 (1-2) ◽  
pp. 49-52 ◽  
Author(s):  
Georg Süssmann
Keyword(s):  
Phase Space ◽  
Quantum State ◽  
Uncertainty Relation ◽  
The Other ◽  
Mixed States ◽  
Von Neumann ◽  
Other Hand ◽  
Pure Quantum State ◽  
Minimum Uncertainty

Abstract The uncertainty area δ (p, q): - [∫ W(p, q)2 dp dq] - 1 is proposed in place of δ p • δ q, and it is shown that each pure quantum state is a minimum uncertainty state in this sense: δ (p, q) = 2 π ħ. For mixed states, on the other hand, δ(p, q) > 2π ħ. In a phase space of 2F(=6N) dimensions, S: = k B • log[δF (p,q)/(2 π ħ)F] whit δF (p,q):= [∫ W(p, q)2 dF p dF q]-1 is considered as an alternative to von Neumann`s entropy S̃:= kB • trc [ρ̂ log (ρ̂-1)].

Comment on ‘‘Obtainment of thermal noise from a pure quantum state’’

1988 ◽  
Vol 38 (3) ◽  
pp. 1657-1658 ◽  
Author(s):  
S. M. Barnett ◽  
P. L. Knight
Keyword(s):  
Quantum State ◽  
Thermal Noise ◽  
Pure Quantum State

Thresholds for reduction-related entanglement criteria in quantum information theory

2015 ◽  
Vol 15 (13&14) ◽  
pp. 1165-1184
Author(s):  
Maria A. Jivulescu ◽  
Nicolae Lupa ◽  
Ion Nechita
Keyword(s):  
Information Theory ◽  
Quantum Information ◽  
Quantum State ◽  
Random Matrix ◽  
Matrix Theory ◽  
Quantum Information Theory ◽  
Quantum States ◽  
Absolute Reduction ◽  
Open Questions ◽  
Pure Quantum State

We consider random bipartite quantum states obtained by tracing out one subsystem from a random, uniformly distributed, tripartite pure quantum state. We compute thresholds for the dimension of the system being traced out, so that the resulting bipartite quantum state satisfies the reduction criterion in different asymptotic regimes. We consider as well the basis-independent version of the reduction criterion (the absolute reduction criterion), computing thresholds for the corresponding eigenvalue sets. We do the same for other sets relevant in the study of absolute separability, using techniques from random matrix theory. Finally, we gather and compare the known values for the thresholds corresponding to different entanglement criteria, and conclude with a list of open questions.

Sign in / Sign up

Export Citation Format

Share Document