## Violation of Ohm’s law in a Weyl metal [A hallmark of the Weyl metal state: Breakdown of Ohm's law]

## Abstract

Ohm’s law is a fundamental paradigm in the electrical transport of metals. Any transport signatures violating Ohm’s law would give an indisputable fingerprint for a novel metallic state. Here, we uncover the breakdown of Ohm’s law owing to a topological structure of the chiral anomaly in the Weyl metal phase. We observe nonlinear *I–V* characteristics in Bi _{0.96}Sb _{0.04} single crystals in the diffusive limit, which occurs only for a magnetic-field-aligned electric field (E∥B). The Boltzmann transport theory with the charge pumping effect reveals the topological-in-origin nonlinear conductivity, and it leads to a universal scaling function of the longitudinal magnetoconductivity, which completely describes our experimental results. Furthermore, as a hallmark of Weyl metals, the nonlinear conductivity provides a venue for nonlinear electronics, optical applications, and the development of a topological Fermi-liquid theory beyond the Landau Fermi-liquid theory.

- Authors:

- Pohang Univ. of Science and Technology (POSTECH), Pohang (Republic of Korea); Institute for Basic Science (IBS), Pohang (Republic of Korea)
- Pohang Univ. of Science and Technology (POSTECH), Pohang (Republic of Korea)
- Yamagata Univ., Yamagata (Japan)
- Florida State Univ., Tallahassee, FL (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Daegu Univ., Gyeonbuk (Korea)

- Publication Date:

- Research Org.:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

- Sponsoring Org.:
- National Science Foundation (NSF); USDOE

- OSTI Identifier:
- 1398920

- Report Number(s):
- LA-UR-17-22745

Journal ID: ISSN 1476-1122

- Grant/Contract Number:
- AC52-06NA25396; IBS-R014-D1; DMR-1157490

- Resource Type:
- Accepted Manuscript

- Journal Name:
- Nature Materials

- Additional Journal Information:
- Journal Volume: 16; Journal ID: ISSN 1476-1122

- Publisher:
- Nature Publishing Group

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 36 MATERIALS SCIENCE

### Citation Formats

```
Shin, Dongwoo, Lee, Yongwoo, Sasaki, M., Jeong, Yoon Hee, Weickert, Franziska, Betts, Jonathan Bobby, Kim, Heon -Jung, Kim, Ki -Seok, and Kim, Jeehoon. Violation of Ohm’s law in a Weyl metal [A hallmark of the Weyl metal state: Breakdown of Ohm's law]. United States: N. p., 2017.
Web. doi:10.1038/nmat4965.
```

```
Shin, Dongwoo, Lee, Yongwoo, Sasaki, M., Jeong, Yoon Hee, Weickert, Franziska, Betts, Jonathan Bobby, Kim, Heon -Jung, Kim, Ki -Seok, & Kim, Jeehoon. Violation of Ohm’s law in a Weyl metal [A hallmark of the Weyl metal state: Breakdown of Ohm's law]. United States. doi:10.1038/nmat4965.
```

```
Shin, Dongwoo, Lee, Yongwoo, Sasaki, M., Jeong, Yoon Hee, Weickert, Franziska, Betts, Jonathan Bobby, Kim, Heon -Jung, Kim, Ki -Seok, and Kim, Jeehoon. Mon .
"Violation of Ohm’s law in a Weyl metal [A hallmark of the Weyl metal state: Breakdown of Ohm's law]". United States. doi:10.1038/nmat4965. https://www.osti.gov/servlets/purl/1398920.
```

```
@article{osti_1398920,
```

title = {Violation of Ohm’s law in a Weyl metal [A hallmark of the Weyl metal state: Breakdown of Ohm's law]},

author = {Shin, Dongwoo and Lee, Yongwoo and Sasaki, M. and Jeong, Yoon Hee and Weickert, Franziska and Betts, Jonathan Bobby and Kim, Heon -Jung and Kim, Ki -Seok and Kim, Jeehoon},

abstractNote = {Ohm’s law is a fundamental paradigm in the electrical transport of metals. Any transport signatures violating Ohm’s law would give an indisputable fingerprint for a novel metallic state. Here, we uncover the breakdown of Ohm’s law owing to a topological structure of the chiral anomaly in the Weyl metal phase. We observe nonlinear I–V characteristics in Bi0.96Sb0.04 single crystals in the diffusive limit, which occurs only for a magnetic-field-aligned electric field (E∥B). The Boltzmann transport theory with the charge pumping effect reveals the topological-in-origin nonlinear conductivity, and it leads to a universal scaling function of the longitudinal magnetoconductivity, which completely describes our experimental results. Furthermore, as a hallmark of Weyl metals, the nonlinear conductivity provides a venue for nonlinear electronics, optical applications, and the development of a topological Fermi-liquid theory beyond the Landau Fermi-liquid theory.},

doi = {10.1038/nmat4965},

journal = {Nature Materials},

number = ,

volume = 16,

place = {United States},

year = {2017},

month = {8}

}

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Web of Science

Works referenced in this record:

##
*Colloquium*: Topological insulators

journal, November 2010

- Hasan, M. Z.; Kane, C. L.
- Reviews of Modern Physics, Vol. 82, Issue 4, p. 3045-3067