Quantum computing: A nano scale information processing in minds and machines

2011 ◽  
Author(s):  
Dwijesh Dutta Majumder ◽  
Sankar Karan
Keyword(s):  
Quantum Computing ◽  
Information Processing ◽  
Nano Scale

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 $\bar{n}\rightarrow\infty$.

NANOSCALE SUPERCONDUCTIVITY

2012 ◽  
Vol 26 (26) ◽  
pp. 1230013 ◽  
Author(s):  
S. P. KRUCHININ ◽  
H. NAGAO
Keyword(s):  
Exact Solution ◽  
Quantum Computing ◽  
Kondo Effect ◽  
Josephson Effect ◽  
High Quality ◽  
Nano Scale ◽  
Research Areas ◽  
Ferromagnetic Particles

We deal with the problem of nanoscale superconductivity. Nanoscale superconductivity remains to be one of the most interesting research areas in condensed mater. Recent technology and experiments have fabricated high-quality superconducting MgB 2 nanoparticles. We consider the two-band superconductivity in ultrasmall grains, by extending the Richardson exact solution to two-band systems, and develop the theory of interactions between nano-scale ferromagnetic particles and superconductors. The properties of nano-sized two-gap superconductors and the Kondo effect in superconducting ultrasmall grains are investigated as well. The theory of the Josephson effect is presented, and his application to quantum computing are analyzed.

Quantum contextuality of YO-13 rays

2021 ◽  
Vol 36 (12) ◽  
pp. 2150088
Author(s):  
Jie Zhou ◽  
Hui-Xian Meng ◽  
Wei-Min Shang ◽  
Jing-Ling Chen
Keyword(s):  
Quantum Computing ◽  
Information Processing ◽  
Quantum Information ◽  
Quantum Correlation ◽  
Quantum Physics ◽  
Quantum Information Processing ◽  
Experimental Tests ◽  
Dimensional System ◽  
Quantum Contextuality ◽  
Fundamental Quantum Physics

Quantum contextuality, a more general quantum correlation, is an important resource for quantum computing and quantum information processing. Meanwhile, quantum contextuality plays an important role in fundamental quantum physics. Yu and Oh (YO) proposed a proof of the Kochen–Specker theorem for a qutrit with only 13 rays. Here, we further study quantum contextuality of YO-13 rays using the inequality approach. The maximum quantum violation value of the optimal noncontextuality inequality constructed by YO-13 rays is increased to 11.9776 in the four-dimensional system, which is larger than 11.6667 in the qutrit system. The result shows that the set of YO-13 rays has stronger quantum contextuality in the four-dimensional system. Moreover, we provide an all-versus-nothing proof (i.e. Hardy-like proof) to study YO-13 rays without using any inequality, which is easily applied to experimental tests. Our results will further deepen the understanding of YO-13 rays.

Sign in / Sign up

Export Citation Format

Share Document