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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 high energy subspace.(a,b) Fidelity F(t), given in Eq. (11), evaluated with the real Hamiltonian (dashed blue curve) and the effective Hamiltonian (solid red curve) acting on the data-bus subspace . The chain of length is N = 3 and the parameters are D = −20J and E = 0 for (a) and E = J for (b). (c) The maximum of bit transfer fidelity Fmax as a function of length N for D = −20J and different values of E. (d) Scaling of the transfer time t* as a function of the length N, using the same parameters of (c).
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f5: Dynamics in high energy subspace.(a,b) Fidelity F(t), given in Eq. (11), evaluated with the real Hamiltonian (dashed blue curve) and the effective Hamiltonian (solid red curve) acting on the data-bus subspace . The chain of length is N = 3 and the parameters are D = −20J and E = 0 for (a) and E = J for (b). (c) The maximum of bit transfer fidelity Fmax as a function of length N for D = −20J and different values of E. (d) Scaling of the transfer time t* as a function of the length N, using the same parameters of (c).

Mentions: We first calculate the fidelity with the Hamiltonian H = Htot, to take account of the influence of the lower-energy subspace on the information transfer in higher energy space. We also compute the fidelity with to check the validity of the effective Hamiltonian in higher-energy subspace. We make a comparison of the time evolutions of the fidelity computed for the total Hamiltonian Htot and the effective Hamiltonian for a spin chain of N = 3 with the parameters D = −20J and E = 0 and J respectively in Fig. 5(a,b). The perfect match of the two curves in Fig. 5(a,b) shows negligible influence of the lower-energy subspace on transfer of the information initially written in the higher-energy subspace along the nano-magnete chain, and thus the higher-energy subspace could function as a data-bus for quantum information transfer.


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 high energy subspace.(a,b) Fidelity F(t), given in Eq. (11), evaluated with the real Hamiltonian (dashed blue curve) and the effective Hamiltonian (solid red curve) acting on the data-bus subspace . The chain of length is N = 3 and the parameters are D = −20J and E = 0 for (a) and E = J for (b). (c) The maximum of bit transfer fidelity Fmax as a function of length N for D = −20J and different values of E. (d) Scaling of the transfer time t* as a function of the length N, using the same parameters of (c).
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f5: Dynamics in high energy subspace.(a,b) Fidelity F(t), given in Eq. (11), evaluated with the real Hamiltonian (dashed blue curve) and the effective Hamiltonian (solid red curve) acting on the data-bus subspace . The chain of length is N = 3 and the parameters are D = −20J and E = 0 for (a) and E = J for (b). (c) The maximum of bit transfer fidelity Fmax as a function of length N for D = −20J and different values of E. (d) Scaling of the transfer time t* as a function of the length N, using the same parameters of (c).
Mentions: We first calculate the fidelity with the Hamiltonian H = Htot, to take account of the influence of the lower-energy subspace on the information transfer in higher energy space. We also compute the fidelity with to check the validity of the effective Hamiltonian in higher-energy subspace. We make a comparison of the time evolutions of the fidelity computed for the total Hamiltonian Htot and the effective Hamiltonian for a spin chain of N = 3 with the parameters D = −20J and E = 0 and J respectively in Fig. 5(a,b). The perfect match of the two curves in Fig. 5(a,b) shows negligible influence of the lower-energy subspace on transfer of the information initially written in the higher-energy subspace along the nano-magnete chain, and thus the higher-energy subspace could function as a data-bus for quantum information transfer.

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