Limits...
Integrated information storage and transfer with a coherent magnetic device.

Jia N, Banchi L, Bayat A, Dong G, Bose S - Sci Rep (2015)

Bottom Line: Quantum systems are inherently dissipation-less, making them excellent candidates even for classical information processing.The proposed mechanism can be realized with different setups.We specifically show that molecular magnets, as the most promising technology, can implement hundreds of operations within their coherence time, while adatoms on surfaces probed by a scanning tunneling microscope is a future possibility.

View Article: PubMed Central - PubMed

Affiliation: State key laboratory of precision spectroscopy, Department of Physics, East China Normal University, Shanghai 200062, China.

ABSTRACT
Quantum systems are inherently dissipation-less, making them excellent candidates even for classical information processing. We propose to use an array of large-spin quantum magnets for realizing a device which has two modes of operation: memory and data-bus. While the weakly interacting low-energy levels are used as memory to store classical information (bits), the high-energy levels strongly interact with neighboring magnets and mediate the spatial movement of information through quantum dynamics. Despite the fact that memory and data-bus require different features, which are usually prerogative of different physical systems--well isolation for the memory cells, and strong interactions for the transmission--our proposal avoids the notorious complexity of hybrid structures. The proposed mechanism can be realized with different setups. We specifically show that molecular magnets, as the most promising technology, can implement hundreds of operations within their coherence time, while adatoms on surfaces probed by a scanning tunneling microscope is a future possibility.

No MeSH data available.


Related in: MedlinePlus

Dynamics in low energy subspace.Storage fidelity Fs(t) in the memory subspace as a function of time for:(a) Different dephasing rates γ and; (b) Different in-plane anisotropy E. In both figures N = 2 and D = −20J.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4561894&req=5

f7: Dynamics in low energy subspace.Storage fidelity Fs(t) in the memory subspace as a function of time for:(a) Different dephasing rates γ and; (b) Different in-plane anisotropy E. In both figures N = 2 and D = −20J.

Mentions: We now study the effect of dephasing on information storage, namely when the system is prepared in the low-energy subspace. To investigate the quality of the storage we define a new fidelity which measures the deviation from the initial state at any time t. For example, we consider the initial pure state and we define the storage fidelity as where ρ(t) is calculated from the master equation (12). In Fig. 7(a) we study the time evolution of the Fs(t) for different values of γ, when E = 0. As expected the storage fidelity decays in time with a rate which increases for increasing γ. However, within the timescale of tens of operations in the computational subspace (say Jt ≈ 100) the quality of the storage is only weakly affected by dephasing, as Fs remains above 0.95 even for a strong dephasing of γ = 0.2J.


Integrated information storage and transfer with a coherent magnetic device.

Jia N, Banchi L, Bayat A, Dong G, Bose S - Sci Rep (2015)

Dynamics in low energy subspace.Storage fidelity Fs(t) in the memory subspace as a function of time for:(a) Different dephasing rates γ and; (b) Different in-plane anisotropy E. In both figures N = 2 and D = −20J.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4561894&req=5

f7: Dynamics in low energy subspace.Storage fidelity Fs(t) in the memory subspace as a function of time for:(a) Different dephasing rates γ and; (b) Different in-plane anisotropy E. In both figures N = 2 and D = −20J.
Mentions: We now study the effect of dephasing on information storage, namely when the system is prepared in the low-energy subspace. To investigate the quality of the storage we define a new fidelity which measures the deviation from the initial state at any time t. For example, we consider the initial pure state and we define the storage fidelity as where ρ(t) is calculated from the master equation (12). In Fig. 7(a) we study the time evolution of the Fs(t) for different values of γ, when E = 0. As expected the storage fidelity decays in time with a rate which increases for increasing γ. However, within the timescale of tens of operations in the computational subspace (say Jt ≈ 100) the quality of the storage is only weakly affected by dephasing, as Fs remains above 0.95 even for a strong dephasing of γ = 0.2J.

Bottom Line: Quantum systems are inherently dissipation-less, making them excellent candidates even for classical information processing.The proposed mechanism can be realized with different setups.We specifically show that molecular magnets, as the most promising technology, can implement hundreds of operations within their coherence time, while adatoms on surfaces probed by a scanning tunneling microscope is a future possibility.

View Article: PubMed Central - PubMed

Affiliation: State key laboratory of precision spectroscopy, Department of Physics, East China Normal University, Shanghai 200062, China.

ABSTRACT
Quantum systems are inherently dissipation-less, making them excellent candidates even for classical information processing. We propose to use an array of large-spin quantum magnets for realizing a device which has two modes of operation: memory and data-bus. While the weakly interacting low-energy levels are used as memory to store classical information (bits), the high-energy levels strongly interact with neighboring magnets and mediate the spatial movement of information through quantum dynamics. Despite the fact that memory and data-bus require different features, which are usually prerogative of different physical systems--well isolation for the memory cells, and strong interactions for the transmission--our proposal avoids the notorious complexity of hybrid structures. The proposed mechanism can be realized with different setups. We specifically show that molecular magnets, as the most promising technology, can implement hundreds of operations within their coherence time, while adatoms on surfaces probed by a scanning tunneling microscope is a future possibility.

No MeSH data available.


Related in: MedlinePlus