Hyperchaos, Intermittency, Noise and Disorder in Modified Semiconductor Superlattices
Weakly coupled semiconductor superlattices under DC voltage bias are nonlinear systems with many degrees of freedom whose nonlinearity is due to sequential tunneling of electrons. They may exhibit spontaneous chaos at room temperature and act as fast physical random number generator devices. Here we...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-11-01
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| Series: | Entropy |
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| Online Access: | https://www.mdpi.com/1099-4300/24/12/1702 |
| _version_ | 1797459311675310080 |
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| author | Luis L. Bonilla Manuel Carretero Emanuel Mompó |
| author_facet | Luis L. Bonilla Manuel Carretero Emanuel Mompó |
| author_sort | Luis L. Bonilla |
| collection | DOAJ |
| description | Weakly coupled semiconductor superlattices under DC voltage bias are nonlinear systems with many degrees of freedom whose nonlinearity is due to sequential tunneling of electrons. They may exhibit spontaneous chaos at room temperature and act as fast physical random number generator devices. Here we present a general sequential transport model with different voltage drops at quantum wells and barriers that includes noise and fluctuations due to the superlattice epitaxial growth. Excitability and oscillations of the current in superlattices with identical periods are due to nucleation and motion of charge dipole waves that form at the emitter contact when the current drops below a critical value. Insertion of wider wells increases superlattice excitability by allowing wave nucleation at the modified wells and more complex dynamics. Then hyperchaos and different types of intermittent chaos are possible on extended DC voltage ranges. Intrinsic shot and thermal noises and external noises produce minor effects on chaotic attractors. However, random disorder due to growth fluctuations may suppress any regular or chaotic current oscillations. Numerical simulations show that more than 70% of samples remain chaotic when the standard deviation of their fluctuations due to epitaxial growth is below 0.024 nm (10% of a single monolayer) whereas for 0.015 nm disorder suppresses chaos. |
| first_indexed | 2024-03-09T16:50:38Z |
| format | Article |
| id | doaj.art-2f95eca0d7c24d5da8977f387616c16b |
| institution | Directory Open Access Journal |
| issn | 1099-4300 |
| language | English |
| last_indexed | 2024-03-09T16:50:38Z |
| publishDate | 2022-11-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Entropy |
| spelling | doaj.art-2f95eca0d7c24d5da8977f387616c16b2023-11-24T14:41:25ZengMDPI AGEntropy1099-43002022-11-012412170210.3390/e24121702Hyperchaos, Intermittency, Noise and Disorder in Modified Semiconductor SuperlatticesLuis L. Bonilla0Manuel Carretero1Emanuel Mompó2Gregorio Millán Institute for Fluid Dynamics, Nanoscience and Industrial Mathematics, Universidad Carlos III de Madrid, 28911 Leganés, SpainGregorio Millán Institute for Fluid Dynamics, Nanoscience and Industrial Mathematics, Universidad Carlos III de Madrid, 28911 Leganés, SpainGregorio Millán Institute for Fluid Dynamics, Nanoscience and Industrial Mathematics, Universidad Carlos III de Madrid, 28911 Leganés, SpainWeakly coupled semiconductor superlattices under DC voltage bias are nonlinear systems with many degrees of freedom whose nonlinearity is due to sequential tunneling of electrons. They may exhibit spontaneous chaos at room temperature and act as fast physical random number generator devices. Here we present a general sequential transport model with different voltage drops at quantum wells and barriers that includes noise and fluctuations due to the superlattice epitaxial growth. Excitability and oscillations of the current in superlattices with identical periods are due to nucleation and motion of charge dipole waves that form at the emitter contact when the current drops below a critical value. Insertion of wider wells increases superlattice excitability by allowing wave nucleation at the modified wells and more complex dynamics. Then hyperchaos and different types of intermittent chaos are possible on extended DC voltage ranges. Intrinsic shot and thermal noises and external noises produce minor effects on chaotic attractors. However, random disorder due to growth fluctuations may suppress any regular or chaotic current oscillations. Numerical simulations show that more than 70% of samples remain chaotic when the standard deviation of their fluctuations due to epitaxial growth is below 0.024 nm (10% of a single monolayer) whereas for 0.015 nm disorder suppresses chaos.https://www.mdpi.com/1099-4300/24/12/1702semiconductor superlatticesnonlinear electron transportchaoshyperchaosintermittencychaos design |
| spellingShingle | Luis L. Bonilla Manuel Carretero Emanuel Mompó Hyperchaos, Intermittency, Noise and Disorder in Modified Semiconductor Superlattices Entropy semiconductor superlattices nonlinear electron transport chaos hyperchaos intermittency chaos design |
| title | Hyperchaos, Intermittency, Noise and Disorder in Modified Semiconductor Superlattices |
| title_full | Hyperchaos, Intermittency, Noise and Disorder in Modified Semiconductor Superlattices |
| title_fullStr | Hyperchaos, Intermittency, Noise and Disorder in Modified Semiconductor Superlattices |
| title_full_unstemmed | Hyperchaos, Intermittency, Noise and Disorder in Modified Semiconductor Superlattices |
| title_short | Hyperchaos, Intermittency, Noise and Disorder in Modified Semiconductor Superlattices |
| title_sort | hyperchaos intermittency noise and disorder in modified semiconductor superlattices |
| topic | semiconductor superlattices nonlinear electron transport chaos hyperchaos intermittency chaos design |
| url | https://www.mdpi.com/1099-4300/24/12/1702 |
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