Ultrafast generation of pseudo-magnetic field for valley excitons in WSe₂ monolayers

Jonghwan Kim¹, Xiaoping Hong¹, Chenhao Jin¹, Su-Fei Shi², Chih-Yuan S Chang³, Ming-Hui Chiu⁴, Lain-Jong Li⁵, Feng Wang⁶

Affiliations

¹ Department of Physics, University of California at Berkeley, Berkeley, CA 94720, USA.
² Department of Physics, University of California at Berkeley, Berkeley, CA 94720, USA. Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
³ Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
⁴ Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
⁵ Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan. Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
⁶ Department of Physics, University of California at Berkeley, Berkeley, CA 94720, USA. Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. Kavli Energy NanoSciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. fengwang76@berkeley.edu.

PMID: 25477455
DOI: 10.1126/science.1258122

Ultrafast generation of pseudo-magnetic field for valley excitons in WSe₂ monolayers

Jonghwan Kim et al. Science. 2014.

. 2014 Dec 5;346(6214):1205-8.

doi: 10.1126/science.1258122.

Authors

Jonghwan Kim¹, Xiaoping Hong¹, Chenhao Jin¹, Su-Fei Shi², Chih-Yuan S Chang³, Ming-Hui Chiu⁴, Lain-Jong Li⁵, Feng Wang⁶

Affiliations

¹ Department of Physics, University of California at Berkeley, Berkeley, CA 94720, USA.
² Department of Physics, University of California at Berkeley, Berkeley, CA 94720, USA. Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
³ Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan.
⁴ Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
⁵ Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan. Physical Sciences and Engineering, King Abdullah University of Science and Technology, Thuwal, Saudi Arabia.
⁶ Department of Physics, University of California at Berkeley, Berkeley, CA 94720, USA. Material Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA. Kavli Energy NanoSciences Institute, University of California Berkeley and Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. fengwang76@berkeley.edu.

PMID: 25477455
DOI: 10.1126/science.1258122

Abstract

The valley pseudospin is a degree of freedom that emerges in atomically thin two-dimensional transition metal dichalcogenides (MX2). The capability to manipulate it, in analogy to the control of spin in spintronics, can open up exciting opportunities. Here, we demonstrate that an ultrafast and ultrahigh valley pseudo-magnetic field can be generated by using circularly polarized femtosecond pulses to selectively control the valley degree of freedom in monolayer MX2. Using ultrafast pump-probe spectroscopy, we observed a pure and valley-selective optical Stark effect in WSe2 monolayers from the nonresonant pump, resulting in an energy splitting of more than 10 milli-electron volts between the K and K' valley exciton transitions. Our study opens up the possibility to coherently manipulate the valley polarization for quantum information applications.

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Ultrafast generation of pseudo-magnetic field for valley excitons in WSe₂ monolayers

Affiliations

Ultrafast generation of pseudo-magnetic field for valley excitons in WSe₂ monolayers

Authors

Affiliations

Abstract

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LinkOut - more resources

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