A new method for determining excited states of quantum systems

1993 ◽  
Vol 15 (2-3) ◽  
pp. 269-277 ◽  
Author(s):  
G. Grosso ◽  
L. Martinelli ◽  
G. Pastori Parravicini
Keyword(s):  
Excited States ◽  
Quantum Systems ◽  
New Method

FRUSTRATED TRANSVERSE ISING MODELS: A CLASS OF FRUSTRATED QUANTUM SYSTEMS

1992 ◽  
Vol 06 (14) ◽  
pp. 2439-2469 ◽  
Author(s):  
P. SEN ◽  
B. K. CHAKRABARTI
Keyword(s):  
Excited States ◽  
Transverse Field ◽  
Ising Models ◽  
Quantum Systems ◽  
Nearest Neighbour ◽  
Competing Interactions ◽  
Annni Model ◽  
Kirkpatrick Model ◽  
Transverse Fields ◽  
Exact Diagonalisation

The analytical and numerical (Monte Carlo and exact diagonalisation) estimates of phase diagrams of frustrated Ising models in transverse fields are discussed here. Specifically we discuss the Sherrington–Kirkpatrick model in transverse field and the Axial Next-Nearest Neighbour Ising (ANNNI) model in transverse field. The effects of quantum fluctuations (induced by the transverse field) on the ground and excited states of such systems with competing interactions (frustration) are also discussed. The results are compared to those available for other frustrated quantum systems.

scholarly journals USE OF THE WHIRLIGIG PRINCIPLE FOR STABILIZING THE INITIAL STATES OF SOME CLASSIC AND QUANTUM SYSTEMS

2020 ◽  
pp. 78-81
Author(s):  
V.A. Buts
Keyword(s):  
Quantum System ◽  
Excited States ◽  
Quantum Systems ◽  
Nuclear Systems ◽  
Initial States

It is shown that the whirligig principle can be used for stabilization of the initial states of some classical and quantum systems. This feature of the whirligig principle is demonstrated by simple examples. The most important result of this work is the proof of the fact that the stabilization of the excited states of quantum systems can be realized by acting not on the quantum system itself, but by acting on the states into which the system must go. Potentially, this result can be used to stabilize excited nuclear systems.

scholarly journals Thermodynamic Cost of Quantum transfers

2021 ◽  
Author(s):  
Forouzan Mirmasoudi ◽  
Sodeif Ahadpour
Keyword(s):  
Excited States ◽  
Energy Cost ◽  
Quantum Fisher Information ◽  
Quantum Correlations ◽  
Spin Squeezing ◽  
Quantum Systems ◽  
Control Parameters ◽  
Dense Coding ◽  
Optimal Dense Coding ◽  
Coding Capacity

Abstract In this work, we will study thermodynamic cost of dense coding. In this regard, a scheme is proposed for quantum channel where is induced from two initially uncorrelated thermal quantum systems. At first, the quantum Fisher information and spin squeezing is used to quantify the correlation dynamics over the system. The system reveals that the dynamics of quantum correlations depends crucially on specific energy and temperature. Also, they can be utilized as control parameters for optimal dense coding. Several interesting features of the variations of the energy cost and the dense coding capacity are obtained. It can keep its own valid capacity value in a broad range of temperature by increasing in the energy value of excited states. Also, we can identify valid dense coding with the help of calculating energy cost in the system. Using this approach, identifying a critical point of this model in dense coding capacity quality can be very effective.

N-TH ROOT OF HERMITE MATRIX AND ITS APPLICATION IN QUANTUM SYSTEMS

2013 ◽  
Vol 27 (22) ◽  
pp. 1350159
Author(s):  
SHI-MIN XU ◽  
XING-LEI XU ◽  
FENG JIANG ◽  
HONG-QI LI
Keyword(s):  
Quantum Mechanics ◽  
Quantum Optics ◽  
Hermitian Matrix ◽  
Quantum Systems ◽  
New Method ◽  
Transformation Behavior ◽  
Mathematical Methods ◽  
Quadratic Hamiltonians ◽  
Hermite Matrix ◽  
Quantum Operators

In this paper, the n-th root of a matrix is defined, and the explicit form of n-th root of an Hermitian matrix is given. A new method for diagonalizing quadratic Hamiltonians is proposed. Also, a class of quantum operators is induced by the linear transformation in configuration space, and its unitary properties and transformation behavior are studied. Our new method based on n-th root of matrices can develop the mathematical methods of quantum mechanics and quantum optics, and can also be applied to engineering, quantum optics and quantum fields states with squeezing properties, as well as the binomial field states.

On the orthogonality condition for the excited states of stationary quantum systems

1968 ◽  
Vol 46 (1) ◽  
pp. 43-47 ◽  
Author(s):  
C. S. Sharma
Keyword(s):  
Perturbation Method ◽  
Excited States ◽  
Quantum Systems ◽  
The State ◽  
Orthogonality Condition ◽  
Perturbation Expansions ◽  
Eigenvalues And Eigenvectors ◽  
Stationary Quantum ◽  
Common Misunderstanding

A theorem establishing the correct orthogonality condition for the perturbation expansions of the state vectors for the excited states of stationary quantum systems is enunciated. A common misunderstanding on this subject is discussed and corrected. Implications of the theorem to the use of the variation perturbation method for calculating approximate eigenvalues and eigenvectors for excited states is discussed.

New method for studying disordered quantum systems

1986 ◽  
Vol 34 (1) ◽  
pp. 189-198 ◽  
Author(s):  
H. G. Schuster ◽  
V. R. Vieira
Keyword(s):  
Quantum Systems ◽  
New Method
Sign in / Sign up

Export Citation Format

Share Document