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Cartoixà X, Colombo L, Rurali R. Thermal Rectification by Design in Telescopic Si Nanowires. NANO LETTERS 2015; 15:8255-8259. [PMID: 26595086 DOI: 10.1021/acs.nanolett.5b03781] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We show that thermal rectification by design is possible by joining/growing Si nanowires (SiNWs) with sections of appropriately selected diameters (i.e., telescopic nanowires). This is done, first, by showing that the heat equation can be applied at the nanoscale (NW diameters down to 5 nm). We (a) obtain thermal conductivity versus temperature, κ(T), curves from molecular dynamics (MD) simulations for SiNWs of three different diameters, then (b) we conduct MD simulations of a telescopic NW built as the junction of two segments with different diameters, and afterward (c) we verify that the MD results for thermal rectification in telescopic NWs are very well reproduced by the heat equation with κ(T) of the segments from MD. Second, we apply the heat equation to predict the amount of thermal rectification in a variety of telescopic SiNWs with segments made from SiNWs where κ(T) has been experimentally measured, obtaining r values up to 50%. This methodology can be applied to predict the thermal rectification of arbitrary heterojunctions as long as the κ(T) data of the constituents are available.
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Affiliation(s)
- Xavier Cartoixà
- Departament d'Enginyeria Electrònica, Universitat Autònoma de Barcelona , 08193 Bellaterra, Barcelona, Spain
| | - Luciano Colombo
- Dipartimento di Fisica, Università di Cagliari, Cittadella Universitaria , 09042 Monserrato (Ca), Italy
| | - Riccardo Rurali
- Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de Bellaterra , 08193 Bellaterra, Barcelona, Spain
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Li Y, Shen X, Wu Z, Huang J, Chen Y, Ni Y, Huang J. Temperature-Dependent Transformation Thermotics: From Switchable Thermal Cloaks to Macroscopic Thermal Diodes. PHYSICAL REVIEW LETTERS 2015; 115:195503. [PMID: 26588397 DOI: 10.1103/physrevlett.115.195503] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2015] [Indexed: 06/05/2023]
Abstract
The macroscopic control of ubiquitous heat flow remains poorly explored due to the lack of a fundamental theoretical method. Here, by establishing temperature-dependent transformation thermotics for treating materials whose conductivity depends on temperature, we show analytical and simulation evidence for switchable thermal cloaking and a macroscopic thermal diode based on the cloaking. The latter allows heat flow in one direction but prohibits the flow in the opposite direction, which is also confirmed by our experiments. Our results suggest that the temperature-dependent transformation thermotics could be a fundamental theoretical method for achieving macroscopic heat rectification, and it could provide guidance both for the macroscopic control of heat flow and for the design of the counterparts of switchable thermal cloaks or macroscopic thermal diodes in other fields like seismology, acoustics, electromagnetics, and matter waves.
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Affiliation(s)
- Ying Li
- Department of Mechanics and Engineering Science, Fudan University, Shanghai 200433, China
| | - Xiangying Shen
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - Zuhui Wu
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - Junying Huang
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - Yixuan Chen
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
| | - Yushan Ni
- Department of Mechanics and Engineering Science, Fudan University, Shanghai 200433, China
| | - Jiping Huang
- Department of Physics, State Key Laboratory of Surface Physics, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Collaborative Innovation Center of Advanced Microstructures, Fudan University, Shanghai 200433, China
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Jing J, Segal D, Li B, Wu LA. Transient unidirectional energy flow and diode-like phenomenon induced by non-Markovian environments. Sci Rep 2015; 5:15332. [PMID: 26478230 PMCID: PMC4609959 DOI: 10.1038/srep15332] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 09/23/2015] [Indexed: 12/02/2022] Open
Abstract
Relying on an exact time evolution scheme, we identify a novel transient energy transfer phenomenon in an exactly-solvable quantum microscopic model consisting of a three-level system coupled to two non-Markovian zero-temperature bosonic baths through two separable quantum channels. The dynamics of this model can be solved exactly using the quantum-state-diffusion equation formalism, demonstrating finite intervals of unidirectional energy flow across the system, typically, from the non-Markovian environment towards the more Markovian bath. Furthermore, when introducing a spatial asymmetry into the system, an analogue of the rectification effect is realized. In the long time limit, the dynamics arrives at a stationary state and the effects recede. Understanding temporal characteristics of directional energy flow will aid in designing microscopic energy transfer devices.
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Affiliation(s)
- Jun Jing
- Institute of Atomic and Molecular Physics and Jilin Provincial Key Laboratory of Applied Atomic and Molecular Spectroscopy, Jilin University, Changchun 130012, Jilin, China.,Department of Theoretical Physics and History of Science, The Basque Country University (EHU/UPV), PO Box 644, and Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain
| | - Dvira Segal
- Chemical Physics Theory Group, Department of Chemistry, University of Toronto, 80 St. George St., Toronto, Ontario M5S 3H6, Canada
| | - Baowen Li
- Department of Physics and Centre for Computational Science and Engineering, National University of Singapore, Singapore 117542, Republic of Singapore
| | - Lian-Ao Wu
- Department of Theoretical Physics and History of Science, The Basque Country University (EHU/UPV), PO Box 644, and Ikerbasque, Basque Foundation for Science, 48011 Bilbao, Spain
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