1
|
Yu Y, Turkowski V, Hachtel JA, Puretzky AA, Ievlev AV, Din NU, Harris SB, Iyer V, Rouleau CM, Rahman TS, Geohegan DB, Xiao K. Anomalous isotope effect on the optical bandgap in a monolayer transition metal dichalcogenide semiconductor. SCIENCE ADVANCES 2024; 10:eadj0758. [PMID: 38381831 PMCID: PMC10881028 DOI: 10.1126/sciadv.adj0758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Accepted: 01/23/2024] [Indexed: 02/23/2024]
Abstract
Isotope effects have received increasing attention in materials science and engineering because altering isotopes directly affects phonons, which can affect both thermal properties and optoelectronic properties of conventional semiconductors. However, how isotopic mass affects the optoelectronic properties in 2D semiconductors remains unclear because of measurement uncertainties resulting from sample heterogeneities. Here, we report an anomalous optical bandgap energy red shift of 13 (±7) milli-electron volts as mass of Mo isotopes is increased in laterally structured 100MoS2-92MoS2 monolayers grown by a two-step chemical vapor deposition that mitigates the effects of heterogeneities. This trend, which is opposite to that observed in conventional semiconductors, is explained by many-body perturbation and time-dependent density functional theories that reveal unusually large exciton binding energy renormalizations exceeding the ground-state renormalization energy due to strong coupling between confined excitons and phonons. The isotope effect on the optical bandgap reported here provides perspective on the important role of exciton-phonon coupling in the physical properties of two-dimensional materials.
Collapse
Affiliation(s)
- Yiling Yu
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
- School of Physics and Technology, Wuhan University, Wuhan 430072, China
| | - Volodymyr Turkowski
- Department of Physics, University of Central Florida, Orlando, FL 32816, USA
| | - Jordan A. Hachtel
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Alexander A. Puretzky
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Anton V. Ievlev
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Naseem U. Din
- Department of Physics, University of Central Florida, Orlando, FL 32816, USA
| | - Sumner B. Harris
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Vasudevan Iyer
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Christopher M. Rouleau
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Talat S. Rahman
- Department of Physics, University of Central Florida, Orlando, FL 32816, USA
| | - David B. Geohegan
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| | - Kai Xiao
- Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| |
Collapse
|
2
|
Montblanch ARP, Barbone M, Aharonovich I, Atatüre M, Ferrari AC. Layered materials as a platform for quantum technologies. NATURE NANOTECHNOLOGY 2023:10.1038/s41565-023-01354-x. [PMID: 37322143 DOI: 10.1038/s41565-023-01354-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Accepted: 02/17/2023] [Indexed: 06/17/2023]
Abstract
Layered materials are taking centre stage in the ever-increasing research effort to develop material platforms for quantum technologies. We are at the dawn of the era of layered quantum materials. Their optical, electronic, magnetic, thermal and mechanical properties make them attractive for most aspects of this global pursuit. Layered materials have already shown potential as scalable components, including quantum light sources, photon detectors and nanoscale sensors, and have enabled research of new phases of matter within the broader field of quantum simulations. In this Review we discuss opportunities and challenges faced by layered materials within the landscape of material platforms for quantum technologies. In particular, we focus on applications that rely on light-matter interfaces.
Collapse
Affiliation(s)
- Alejandro R-P Montblanch
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- QuTech and Kavli Institute of Nanoscience, Delft University of Technology, Delft, The Netherlands
| | - Matteo Barbone
- Cavendish Laboratory, University of Cambridge, Cambridge, UK
- Cambridge Graphene Centre, University of Cambridge, Cambridge, UK
- Munich Center for Quantum Science and Technology, (MCQST), Munich, Germany
- Walter Schottky Institut and Department of Electrical and Computer Engineering, Technische Universität München, Garching, Germany
| | - Igor Aharonovich
- School of Mathematical and Physical Sciences, University of Technology Sydney, Ultimo, New South Wales, Sydney, Australia
- Australian Research Council Centre of Excellence for Transformative Meta-Optical Systems, University of Technology Sydney, Ultimo, New South Wales, Sydney, Australia
| | - Mete Atatüre
- Cavendish Laboratory, University of Cambridge, Cambridge, UK.
| | - Andrea C Ferrari
- Cambridge Graphene Centre, University of Cambridge, Cambridge, UK.
| |
Collapse
|
3
|
Shamirzaev TS, Shumilin AV, Smirnov DS, Kudlacik D, Nekrasov SV, Kusrayev YG, Yakovlev DR, Bayer M. Optical Orientation of Excitons in a Longitudinal Magnetic Field in Indirect-Band-Gap (In,Al)As/AlAs Quantum Dots with Type-I Band Alignment. NANOMATERIALS (BASEL, SWITZERLAND) 2023; 13:729. [PMID: 36839097 PMCID: PMC9963670 DOI: 10.3390/nano13040729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 02/06/2023] [Accepted: 02/10/2023] [Indexed: 06/18/2023]
Abstract
Exciton recombination and spin dynamics in (In,Al)As/AlAs quantum dots (QDs) with indirect band gap and type-I band alignment were studied. The negligible (less than 0.2 μeV) value of the anisotropic exchange interaction in these QDs prevents the mixing of the excitonic basis states and makes the formation of spin-polarized bright excitons possible under quasi-resonant, circularly polarized excitation. The recombination and spin dynamics of excitons are controlled by the hyperfine interaction between the electron and nuclear spins. A QD blockade by dark excitons was observed in the magnetic field, that eliminates the impact of nuclear spin fluctuations. A kinetic model which accounts for the population dynamics of the bright and dark exciton states as well as for the spin dynamics was developed to quantitatively describe the experimental data.
Collapse
Affiliation(s)
- T. S. Shamirzaev
- Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Novosibirsk State University, 630090 Novosibirsk, Russia
| | - A. V. Shumilin
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - D. S. Smirnov
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - D. Kudlacik
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - S. V. Nekrasov
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - Yu G. Kusrayev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - D. R. Yakovlev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| | - M. Bayer
- Experimentelle Physik 2, Technische Universität Dortmund, 44227 Dortmund, Germany
| |
Collapse
|
4
|
Leppenen NV, Smirnov DS. Optical measurement of electron spins in quantum dots: quantum Zeno effects. NANOSCALE 2022; 14:13284-13291. [PMID: 36062980 DOI: 10.1039/d2nr01241c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
We describe theoretically the effects of the quantum back action under the continuous optical measurement of electron spins in quantum dots. We consider the system excitation by elliptically polarized light close to the trion resonance, which allows for simultaneous spin orientation and measurement. We microscopically demonstrate that the nuclei-induced spin relaxation can be both suppressed and accelerated by the continuous spin measurement due to the quantum Zeno and anti-Zeno effects, respectively. Our theoretical predictions can be directly compared with the future experimental results and straightforwardly generalized for pump-probe experiments.
Collapse
Affiliation(s)
| | - D S Smirnov
- Ioffe Institute, 194021 St. Petersburg, Russia.
| |
Collapse
|
5
|
Jiang M, Wu Z, Yang Q, Zhang Y, Men Y, Jia T, Sun Z, Feng D. Coherent Spin Dynamics of Localized Electrons in Monolayer MoS 2. J Phys Chem Lett 2022; 13:2661-2667. [PMID: 35298166 DOI: 10.1021/acs.jpclett.2c00329] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Compared with itinerant electrons in monolayer transition-metal dichalcogenides, localized electrons exhibit coherent spin precession in transverse magnetic fields B and usually have longer spin relaxation times. Here, we uncover the intrinsic spin dephasing processes of localized electrons whose mechanism remains unclear. Electron spin coherence dynamics are studied by time-resolved Faraday rotation spectroscopy in monolayer MoS2, where four subensembles of localized electrons are found with different g factor values and inhomogeneous broadening. The spin dephasing rates of all four subensembles include a linearly B-dependent part due to g-factor inhomogeneity and a B-independent part dominated by electron-nuclear hyperfine interaction and/or anisotropic exchange interaction. The hyperfine-induced spin dephasing time is ∼30-40 ns, and the anisotropic exchange-induced spin dephasing time is on the order of subnanoseconds. The findings give insight into the coherent spin dynamics of localized electrons in monolayers and the interaction between the electron spin and its environment.
Collapse
Affiliation(s)
- Meizhen Jiang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Zhen Wu
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Qing Yang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Yuanyuan Zhang
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Yumeng Men
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Tianqing Jia
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Zhenrong Sun
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
| | - Donghai Feng
- State Key Laboratory of Precision Spectroscopy, East China Normal University, Shanghai 200241, China
- Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China
| |
Collapse
|
6
|
Smirnov DS, Shamirzaev TS, Yakovlev DR, Bayer M. Dynamic Polarization of Electron Spins Interacting with Nuclei in Semiconductor Nanostructures. PHYSICAL REVIEW LETTERS 2020; 125:156801. [PMID: 33095603 DOI: 10.1103/physrevlett.125.156801] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Accepted: 08/28/2020] [Indexed: 06/11/2023]
Abstract
We suggest a new spin orientation mechanism for localized electrons: dynamic electron spin polarization provided by nuclear spin fluctuations. The detrimental effect of nuclear spin fluctuations can be harnessed and employed to provide angular momentum for the electrons via the hyperfine interaction in a weak magnetic field. For this, the sample is illuminated by an unpolarized light, which directly polarizes neither the electrons nor the nuclei. We predict that, for the electrons bound in localized excitons, 100% spin polarization can be reached in longitudinal magnetic fields of a few millitesla. The proof of principle experiment is performed on momentum-indirect excitons in (In,Al)As/AlAs quantum dots, where in a magnetic field of 17 mT the electron spin polarization of 30% is measured.
Collapse
Affiliation(s)
- D S Smirnov
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
| | - T S Shamirzaev
- Rzhanov Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, 630090 Novosibirsk, Russia
- Ural Federal University, 620002 Yekaterinburg, Russia
| | - D R Yakovlev
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
| | - M Bayer
- Ioffe Institute, Russian Academy of Sciences, 194021 St. Petersburg, Russia
- Experimentelle Physik 2, Technische Universität Dortmund, 44221 Dortmund, Germany
| |
Collapse
|