1
|
Xiao Y, Wu J, Dadap JI, Awan KM, Yang D, Liang J, Watanabe K, Taniguchi T, Zonno M, Bluschke M, Eisaki H, Greven M, Damascelli A, Ye Z. Optically Probing Unconventional Superconductivity in Atomically Thin Bi 2Sr 2Ca 0.92Y 0.08Cu 2O 8+δ. Nano Lett 2024; 24:3986-3993. [PMID: 38501960 DOI: 10.1021/acs.nanolett.4c00559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
Atomically thin cuprates exhibiting a superconducting phase transition temperature similar to that of the bulk have recently been realized, although the device fabrication remains a challenge and limits the potential for many novel studies and applications. Here, we use an optical pump-probe approach to noninvasively study the unconventional superconductivity in atomically thin Bi2Sr2Ca0.92Y0.08Cu2O8+δ (Y-Bi2212). Apart from finding an optical response due to the superconducting phase transition that is similar to that of bulk Y-Bi2212, we observe that the sign and amplitude of the pump-probe signal in atomically thin flakes vary significantly in different dielectric environments depending on the nature of the optical excitation. By exploiting the spatial resolution of the optical probe, we uncover the exceptional sensitivity of monolayer Y-Bi2212 to the environment. Our results provide the first optical evidence for the intralayer nature of the superconducting condensate in Bi2212 and highlight the role of double-sided encapsulation in preserving superconductivity in atomically thin cuprates.
Collapse
Affiliation(s)
- Yunhuan Xiao
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Jingda Wu
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Jerry I Dadap
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Kashif Masud Awan
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Dongyang Yang
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Jing Liang
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Marta Zonno
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Martin Bluschke
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Hiroshi Eisaki
- Nanoelectronics Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8568, Japan
| | - Martin Greven
- School of Physics and Astronomy, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Andrea Damascelli
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Ziliang Ye
- Department of Physics & Astronomy, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
- Quantum Matter Institute, University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| |
Collapse
|
2
|
Yang D, Liang J, Wu J, Xiao Y, Dadap JI, Watanabe K, Taniguchi T, Ye Z. Non-volatile electrical polarization switching via domain wall release in 3R-MoS 2 bilayer. Nat Commun 2024; 15:1389. [PMID: 38360848 PMCID: PMC10869714 DOI: 10.1038/s41467-024-45709-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 02/02/2024] [Indexed: 02/17/2024] Open
Abstract
Understanding the nature of sliding ferroelectricity is of fundamental importance for the discovery and application of two-dimensional ferroelectric materials. In this work, we investigate the phenomenon of switchable polarization in a bilayer MoS2 with natural rhombohedral stacking, where the spontaneous polarization is coupled with excitonic effects through asymmetric interlayer coupling. Using optical spectroscopy and imaging techniques, we observe how a released domain wall switches the polarization of a large single domain. Our results highlight the importance of domain walls in the polarization switching of non-twisted rhombohedral transition metal dichalcogenides and open new opportunities for the non-volatile control of their optical response.
Collapse
Affiliation(s)
- Dongyang Yang
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC, Canada
| | - Jing Liang
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC, Canada
| | - Jingda Wu
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC, Canada
| | - Yunhuan Xiao
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC, Canada
| | - Jerry I Dadap
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC, Canada
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, Tsukuba, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Tsukuba, Japan
| | - Ziliang Ye
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC, Canada.
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC, Canada.
| |
Collapse
|
3
|
Liang J, Yang D, Xiao Y, Chen S, Dadap JI, Rottler J, Ye Z. Shear Strain-Induced Two-Dimensional Slip Avalanches in Rhombohedral MoS 2. Nano Lett 2023; 23:7228-7235. [PMID: 37358360 DOI: 10.1021/acs.nanolett.3c01487] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Slip avalanches are ubiquitous phenomena occurring in three-dimensional materials under shear strain, and their study contributes immensely to our understanding of plastic deformation, fragmentation, and earthquakes. So far, little is known about the role of shear strain in two-dimensional (2D) materials. Here we show some evidence of 2D slip avalanches in exfoliated rhombohedral MoS2, triggered by shear strain near the threshold level. Utilizing interfacial polarization in 3R-MoS2, we directly probe the stacking order in multilayer flakes and discover a wide variety of polarization domains with sizes following a power-law distribution. These findings suggest that slip avalanches can occur during the exfoliation of 2D materials, and the stacking orders can be changed via shear strain. Our observation has far-reaching implications for the development of new materials and technologies, where precise control over the atomic structure of these materials is essential for optimizing their properties as well as for our understanding of fundamental physical phenomena.
Collapse
Affiliation(s)
- Jing Liang
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Dongyang Yang
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Yunhuan Xiao
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Sean Chen
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Jerry I Dadap
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Joerg Rottler
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| | - Ziliang Ye
- Department of Physics and Astronomy, The University of British Columbia, Vancouver, BC V6T 1Z1, Canada
- Quantum Matter Institute, The University of British Columbia, Vancouver, BC V6T 1Z4, Canada
| |
Collapse
|
4
|
Qian Y, Brown JB, Huang-Fu ZC, Zhang T, Wang H, Wang S, Dadap JI, Rao Y. Reply to: A discrepancy of 10 7 in experimental and theoretical density detection limits of aerosol particles by surface nonlinear light scattering. Commun Chem 2023; 6:115. [PMID: 37291188 DOI: 10.1038/s42004-023-00904-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 05/15/2023] [Indexed: 06/10/2023] Open
Affiliation(s)
- Yuqin Qian
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, 84322, USA
| | - Jesse B Brown
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, 84322, USA
| | - Zhi-Chao Huang-Fu
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, 84322, USA
| | - Tong Zhang
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, 84322, USA
| | - Hui Wang
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, 84322, USA
| | - ShanYi Wang
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, 84322, USA
- Department of Physics and Astronomy, Barnard College, New York, NY, 10027, USA
| | - Jerry I Dadap
- Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, V6T 1Z4, BC, Canada
| | - Yi Rao
- Department of Chemistry and Biochemistry, Utah State University, Logan, UT, 84322, USA.
| |
Collapse
|
5
|
Wu J, Yang D, Liang J, Werner M, Ostroumov E, Xiao Y, Watanabe K, Taniguchi T, Dadap JI, Jones D, Ye Z. Ultrafast response of spontaneous photovoltaic effect in 3R-MoS 2-based heterostructures. Sci Adv 2022; 8:eade3759. [PMID: 36525495 PMCID: PMC9757740 DOI: 10.1126/sciadv.ade3759] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 11/14/2022] [Indexed: 06/17/2023]
Abstract
Rhombohedrally stacked MoS2 has been shown to exhibit spontaneous polarization down to the bilayer limit and can sustain a strong depolarization field when sandwiched between graphene. Such a field gives rise to a spontaneous photovoltaic effect without needing any p-n junction. In this work, we show that the photovoltaic effect has an external quantum efficiency of 10% for devices with only two atomic layers of MoS2 at low temperatures, and identify a picosecond-fast photocurrent response, which translates to an intrinsic device bandwidth at ∼100-GHz level. To this end, we have developed a nondegenerate pump-probe photocurrent spectroscopy technique to deconvolute the thermal and charge-transfer processes, thus successfully revealing the multicomponent nature of the photocurrent dynamics. The fast component approaches the limit of the charge-transfer speed at the graphene-MoS2 interface. The remarkable efficiency and ultrafast photoresponse in the graphene-3R-MoS2 devices support the use of ferroelectric van der Waals materials for future high-performance optoelectronic applications.
Collapse
Affiliation(s)
- Jingda Wu
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, The University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - Dongyang Yang
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, The University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - Jing Liang
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, The University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - Max Werner
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, The University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - Evgeny Ostroumov
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, The University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - Yunhuan Xiao
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, The University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - Kenji Watanabe
- Research Center for Functional Materials, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Takashi Taniguchi
- International Center for Materials Nanoarchitectonics, National Institute for Materials Science, 1-1 Namiki, Tsukuba 305-0044, Japan
| | - Jerry I. Dadap
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, The University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - David Jones
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, The University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada
| | - Ziliang Ye
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, BC V6T 1Z1, Canada
- Stewart Blusson Quantum Matter Institute, The University of British Columbia, 2355 East Mall, Vancouver, BC V6T 1Z4, Canada
| |
Collapse
|
6
|
Qian Y, Brown JB, Huang-Fu ZC, Zhang T, Wang H, Wang S, Dadap JI, Rao Y. In situ analysis of the bulk and surface chemical compositions of organic aerosol particles. Commun Chem 2022; 5:58. [PMID: 36698010 PMCID: PMC9814772 DOI: 10.1038/s42004-022-00674-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Accepted: 04/12/2022] [Indexed: 01/28/2023] Open
Abstract
Understanding the chemical and physical properties of particles is an important scientific, engineering, and medical issue that is crucial to air quality, human health, and environmental chemistry. Of special interest are aerosol particles floating in the air for both indoor virus transmission and outdoor atmospheric chemistry. The growth of bio- and organic-aerosol particles in the air is intimately correlated with chemical structures and their reactions in the gas phase at aerosol particle surfaces and in-particle phases. However, direct measurements of chemical structures at aerosol particle surfaces in the air are lacking. Here we demonstrate in situ surface-specific vibrational sum frequency scattering (VSFS) to directly identify chemical structures of molecules at aerosol particle surfaces. Furthermore, our setup allows us to simultaneously probe hyper-Raman scattering (HRS) spectra in the particle phase. We examined polarized VSFS spectra of propionic acid at aerosol particle surfaces and in particle bulk. More importantly, the surface adsorption free energy of propionic acid onto aerosol particles was found to be less negative than that at the air/water interface. These results challenge the long-standing hypothesis that molecular behaviors at the air/water interface are the same as those at aerosol particle surfaces. Our approach opens a new avenue in revealing surface compositions and chemical aging in the formation of secondary organic aerosols in the atmosphere as well as chemical analysis of indoor and outdoor viral aerosol particles.
Collapse
Affiliation(s)
- Yuqin Qian
- grid.53857.3c0000 0001 2185 8768Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322 USA
| | - Jesse B. Brown
- grid.53857.3c0000 0001 2185 8768Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322 USA
| | - Zhi-Chao Huang-Fu
- grid.53857.3c0000 0001 2185 8768Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322 USA
| | - Tong Zhang
- grid.53857.3c0000 0001 2185 8768Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322 USA
| | - Hui Wang
- grid.53857.3c0000 0001 2185 8768Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322 USA ,grid.8547.e0000 0001 0125 2443Department of Chemistry, Fudan University, Shanghai, 200433 China
| | - ShanYi Wang
- grid.53857.3c0000 0001 2185 8768Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322 USA ,grid.470930.90000 0001 2182 2351Department of Physics and Astronomy, Barnard College, New York, NY 10027 USA
| | - Jerry I. Dadap
- grid.17091.3e0000 0001 2288 9830Stewart Blusson Quantum Matter Institute, University of British Columbia, Vancouver, BC V6T 1Z4 Canada
| | - Yi Rao
- grid.53857.3c0000 0001 2185 8768Department of Chemistry and Biochemistry, Utah State University, Logan, UT 84322 USA
| |
Collapse
|
7
|
Ahmed A, Yang H, Rothenberg JM, Souhan B, Wang Z, Abrams NC, Meng X, Ingold KA, Evans CC, Hensley JM, Bergman K, Grote RR, Knights AP, Dadap JI, Osgood RM. Differential phase-shift-keying demodulation by coherent perfect absorption in silicon photonics. Opt Lett 2018; 43:4061-4064. [PMID: 30106952 DOI: 10.1364/ol.43.004061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 07/10/2018] [Indexed: 06/08/2023]
Abstract
We demonstrate a novel differential phase-shift-keying (DPSK) demodulator based on coherent perfect absorption (CPA). Our DPSK demodulator chip device, which incorporates a silicon ring resonator, two bus waveguide inputs, and monolithically integrated detectors, operates passively at a bit rate of 10 Gbps at telecommunication wavelengths, and fits within a mm-scale footprint. Critical coupling is used to achieve efficient CPA by tuning the gap between the ring and bus waveguides. The device has a vertical eye opening of 12.47 mV and a quality factor exceeding 3×104. The fundamental principle behind this photonic circuit can be extended to other formats of integrated demodulators.
Collapse
|
8
|
Meng X, Jin W, Yang H, Dadap JI, Osgood RM, Dolocan A, Sutter P, Camillone N. Two-color field enhancement at an STM junction for spatiotemporally resolved photoemission. Opt Lett 2017; 42:2651-2654. [PMID: 28957307 DOI: 10.1364/ol.42.002651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 06/04/2017] [Indexed: 06/07/2023]
Abstract
We report measurements and numerical simulations of ultrafast laser-excited carrier flow across a scanning tunneling microscope (STM) junction. The current from a nanoscopic tungsten tip across a ∼1 nm vacuum gap to a silver surface is driven by a two-color excitation scheme that uses an optical delay-modulation technique to extract the two-color signal from background contributions. The role of optical field enhancements in driving the current is investigated using density functional theory and full three-dimensional finite-difference time-domain computations. We find that simulated field-enhanced two-photon photoemission (2PPE) currents are in excellent agreement with the observed exponential decay of the two-color photoexcited current with increasing tip-surface separation, as well as its optical-delay dependence. The results suggest an approach to 2PPE with simultaneous subpicosecond temporal and nanometer spatial resolution.
Collapse
|
9
|
Rhodes D, Chenet DA, Janicek BE, Nyby C, Lin Y, Jin W, Edelberg D, Mannebach E, Finney N, Antony A, Schiros T, Klarr T, Mazzoni A, Chin M, Chiu YC, Zheng W, Zhang QR, Ernst F, Dadap JI, Tong X, Ma J, Lou R, Wang S, Qian T, Ding H, Osgood RM, Paley DW, Lindenberg AM, Huang PY, Pasupathy AN, Dubey M, Hone J, Balicas L. Engineering the Structural and Electronic Phases of MoTe 2 through W Substitution. Nano Lett 2017; 17:1616-1622. [PMID: 28145719 DOI: 10.1021/acs.nanolett.6b04814] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
MoTe2 is an exfoliable transition metal dichalcogenide (TMD) that crystallizes in three symmetries: the semiconducting trigonal-prismatic 2H- or α-phase, the semimetallic and monoclinic 1T'- or β-phase, and the semimetallic orthorhombic γ-structure. The 2H-phase displays a band gap of ∼1 eV making it appealing for flexible and transparent optoelectronics. The γ-phase is predicted to possess unique topological properties that might lead to topologically protected nondissipative transport channels. Recently, it was argued that it is possible to locally induce phase-transformations in TMDs, through chemical doping, local heating, or electric-field to achieve ohmic contacts or to induce useful functionalities such as electronic phase-change memory elements. The combination of semiconducting and topological elements based upon the same compound might produce a new generation of high performance, low dissipation optoelectronic elements. Here, we show that it is possible to engineer the phases of MoTe2 through W substitution by unveiling the phase-diagram of the Mo1-xWxTe2 solid solution, which displays a semiconducting to semimetallic transition as a function of x. We find that a small critical W concentration xc ∼ 8% stabilizes the γ-phase at room temperature. This suggests that crystals with x close to xc might be particularly susceptible to phase transformations induced by an external perturbation, for example, an electric field. Photoemission spectroscopy, indicates that the γ-phase possesses a Fermi surface akin to that of WTe2.
Collapse
Affiliation(s)
- D Rhodes
- National High Magnetic Field Laboratory, Florida State University , Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University , Tallahassee, Florida 32306, United States
| | - D A Chenet
- Department of Mechanical Engineering, Columbia University , New York, New York 10027, United States
| | - B E Janicek
- Department of Materials Science and Engineering, University of Illinois Urbana-Champaign , Urbana, Illinois 61801, United States
| | - C Nyby
- Department of Chemistry, Stanford University , Stanford, California 94305-4401, United States
| | | | | | | | - E Mannebach
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
| | - N Finney
- Department of Mechanical Engineering, Columbia University , New York, New York 10027, United States
| | - A Antony
- Department of Mechanical Engineering, Columbia University , New York, New York 10027, United States
| | - T Schiros
- Materials Research Science and Engineering Center, Columbia University , New York, New York 10027 United States
- Department of Science and Mathematics, SUNY Fashion Institute of Technology , New York, New York 10001 United States
| | - T Klarr
- Sensors and Electronic Devices Directorate, United States Army Research Laboratory , Adelphi, Maryland 20723, United States
| | - A Mazzoni
- Sensors and Electronic Devices Directorate, United States Army Research Laboratory , Adelphi, Maryland 20723, United States
| | - M Chin
- Sensors and Electronic Devices Directorate, United States Army Research Laboratory , Adelphi, Maryland 20723, United States
| | - Y-C Chiu
- National High Magnetic Field Laboratory, Florida State University , Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University , Tallahassee, Florida 32306, United States
| | - W Zheng
- National High Magnetic Field Laboratory, Florida State University , Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University , Tallahassee, Florida 32306, United States
| | - Q R Zhang
- National High Magnetic Field Laboratory, Florida State University , Tallahassee, Florida 32310, United States
- Department of Physics, Florida State University , Tallahassee, Florida 32306, United States
| | - F Ernst
- Department of Applied Physics, Stanford University , Stanford, California 94305-4090, United States
- Stanford PULSE Institute, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
| | - J I Dadap
- Department of Electrical Engineering, Columbia University , New York, New York 10027, United States
| | - X Tong
- Center for Functional Nanomaterials, Brookhaven National Laboratory , Upton, New York 11973-5000, United States
| | - J Ma
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - R Lou
- Department of Physics, Renmin University of China , Beijing 100872, China
| | - S Wang
- Department of Physics, Renmin University of China , Beijing 100872, China
| | - T Qian
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - H Ding
- Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences , Beijing 100190, China
| | - R M Osgood
- Department of Electrical Engineering, Columbia University , New York, New York 10027, United States
| | | | - A M Lindenberg
- Department of Materials Science and Engineering, Stanford University , Stanford, California 94305, United States
- Stanford PULSE Institute, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory , Menlo Park, California 94025, United States
| | - P Y Huang
- Department of Mechanical Science and Engineering, University of Illinois Urbana-Champaign , Urbana, Illinois 61801, United States
| | | | - M Dubey
- Sensors and Electronic Devices Directorate, United States Army Research Laboratory , Adelphi, Maryland 20723, United States
| | - J Hone
- Department of Mechanical Engineering, Columbia University , New York, New York 10027, United States
| | - L Balicas
- National High Magnetic Field Laboratory, Florida State University , Tallahassee, Florida 32310, United States
| |
Collapse
|
10
|
Meng X, Grote RR, Jin W, Dadap JI, Panoiu NC, Osgood RM. Rigorous theoretical analysis of a surface-plasmon nanolaser with monolayer MoS 2 gain medium. Opt Lett 2016; 41:2636-2639. [PMID: 27244433 DOI: 10.1364/ol.41.002636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Lasers based on monolayer (ML) transition-metal dichalcogenide semiconductor crystals have the potential for low threshold operation and a small device footprint; however, nanophotonic engineering is required to maximize the interaction between the optical fields and the three-atom-thick gain medium. Here, we develop a theoretical model to design a direct bandgap optically pumped nanophotonic integrated laser. Our device utilizes a gap-surface-plasmon optical mode to achieve subwavelength optical confinement and consists of a high-index GaP nanowire atop an ML MoS2 film on an Ag substrate. The optical field and material medium are analyzed using a three dimensional finite-difference time-domain method and a first-principles calculation based on the density functional theory, respectively. The nanolaser is designed to have a threshold of ∼0.6 μW under quasi-continuous wave operation on an excitonic transition at room temperature.
Collapse
|
11
|
Rothenberg JM, Chen CP, Ackert JJ, Dadap JI, Knights AP, Bergman K, Osgood RM, Grote RR. Experimental demonstration of coherent perfect absorption in a silicon photonic racetrack resonator. Opt Lett 2016; 41:2537-40. [PMID: 27244408 DOI: 10.1364/ol.41.002537] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We present the first experimental demonstration of coherent perfect absorption (CPA) in an integrated device using a silicon racetrack resonator at telecommunication wavelengths. Absorption in the racetrack is achieved by Si+-ion-implantation, allowing for phase controllable amplitude modulation at the resonant wavelength. The device is measured to have an extinction of 24.5 dB and a quality-factor exceeding 3000. Our results will enable integrated CPA devices for data modulation and detection.
Collapse
|
12
|
Yeh PC, Jin W, Zaki N, Kunstmann J, Chenet D, Arefe G, Sadowski JT, Dadap JI, Sutter P, Hone J, Osgood RM. Direct Measurement of the Tunable Electronic Structure of Bilayer MoS2 by Interlayer Twist. Nano Lett 2016; 16:953-959. [PMID: 26760447 DOI: 10.1021/acs.nanolett.5b03883] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Using angle-resolved photoemission on micrometer-scale sample areas, we directly measure the interlayer twist angle-dependent electronic band structure of bilayer molybdenum-disulfide (MoS2). Our measurements, performed on arbitrarily stacked bilayer MoS2 flakes prepared by chemical vapor deposition, provide direct evidence for a downshift of the quasiparticle energy of the valence band at the Brillouin zone center (Γ̅ point) with the interlayer twist angle, up to a maximum of 120 meV at a twist angle of ∼40°. Our direct measurements of the valence band structure enable the extraction of the hole effective mass as a function of the interlayer twist angle. While our results at Γ̅ agree with recently published photoluminescence data, our measurements of the quasiparticle spectrum over the full 2D Brillouin zone reveal a richer and more complicated change in the electronic structure than previously theoretically predicted. The electronic structure measurements reported here, including the evolution of the effective mass with twist-angle, provide new insight into the physics of twisted transition-metal dichalcogenide bilayers and serve as a guide for the practical design of MoS2 optoelectronic and spin-/valley-tronic devices.
Collapse
Affiliation(s)
- Po-Chun Yeh
- Department of Electrical Engineering, Columbia University , New York, New York 10027, United States
| | - Wencan Jin
- Department of Applied Physics and Applied Mathematics, Columbia University , New York, New York 10027, United States
| | - Nader Zaki
- Department of Applied Physics and Applied Mathematics, Columbia University , New York, New York 10027, United States
| | - Jens Kunstmann
- Department of Chemistry, Columbia University , New York, New York 10027, United States
- Theoretical Chemistry, TU Dresden , 01062 Dresden, Germany
| | - Daniel Chenet
- Department of Mechanical Engineering, Columbia University , New York, New York 10027, United States
| | - Ghidewon Arefe
- Department of Mechanical Engineering, Columbia University , New York, New York 10027, United States
| | - Jerzy T Sadowski
- Center for Functional Nanomaterials, Brookhaven National Laboratory , Upton, New York 11973, United States
| | - Jerry I Dadap
- Department of Electrical Engineering, Columbia University , New York, New York 10027, United States
| | - Peter Sutter
- Department of Electrical and Computer Engineering, University of Nebraska-Lincoln , Lincoln, Nebraska 68588, United States
| | - James Hone
- Department of Mechanical Engineering, Columbia University , New York, New York 10027, United States
| | - Richard M Osgood
- Department of Electrical Engineering, Columbia University , New York, New York 10027, United States
- Department of Applied Physics and Applied Mathematics, Columbia University , New York, New York 10027, United States
| |
Collapse
|
13
|
Abstract
We introduce the notion of dissipative optical parametric amplifiers (DOPA) and demonstrate that, even in the absence of the Hermitian phase-matching condition in these structures, the signal beam can be amplified when the idler mode suffers optical attenuation. We discuss the optical implementation of this concept in waveguide platforms, and we propose different methods to control the optical loss of these configurations only at the wavelength of the idler component. Surprisingly, this spectrally selective dissipation process allows the signal beam to draw more energy from the pump and, as a result, attains net amplification. Similar results also apply if the losses are introduced only to the signal component. This intriguing feature can open new avenues for building long wavelength light sources and parametric amplifiers by using semiconductor planar structures, where Hermitian phase-matching requirements can be difficult to satisfy without adding stringent geometric constraints or relatively complex fabrication steps.
Collapse
|
14
|
Meng X, Grote RR, Dadap JI, Panoiu NC, Osgood RM. Engineering metal-nanoantennae/dye complexes for maximum fluorescence enhancement. Opt Express 2014; 22:22018-22030. [PMID: 25321576 DOI: 10.1364/oe.22.022018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We theoretically investigate the fluorescence enhancement of a molecule placed in a variable (4 - 20 nm) gap of a plasmonic dimer, with different dye molecules as well as different nanoparticle geometries, using a fully vectorial three-dimensional finite-difference time-domain (3D FDTD) method. This work extends previous studies on molecular fluorescence in the vicinity of metal interfaces and single nanoparticles and shows how the radiative emission of a molecule can be further enhanced by engineering the geometry of a plasmonic structure. Through the use of rigorous 3D FDTD calculations, in conjunction with analytic guidance based on temporal coupled-mode (TCM) theory, we develop a design procedure for antennae assemblies that is useful both for general understanding of molecule-metal structure interaction and experimental efforts in plasmon-enhanced molecular spectroscopy.
Collapse
|
15
|
Huang HC, Dadap JI, Malladi G, Kymissis I, Bakhru H, Osgood RM. Helium-ion-induced radiation damage in LiNbO₃ thin-film electro-optic modulators. Opt Express 2014; 22:19653-19661. [PMID: 25321048 DOI: 10.1364/oe.22.019653] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Helium-ion-induced radiation damage in a LiNbO3-thin-film (10 μm-thick) modulator is experimentally investigated. The results demonstrate a degradation of the device performance in the presence of He(+) irradiation at doses of ≥ 10(16) cm(-2). The experiments also show that the presence of the He(+) stopping region, which determines the degree of overlap between the ion-damaged region and the guided optical mode, plays a major role in determining the degree of degradation in modulation performance. Our measurements showed that the higher overlap can lead to an additional ~5.5 dB propagation loss. The irradiation-induced change of crystal-film anisotropy(n(o)-n(e))of ~36% was observed for the highest dose used in the experiments. The relevant device extinction ratio, V(π)L, and device insertion loss, as well the damage mechanisms of each of these parameters are also reported and discussed.
Collapse
|
16
|
Driscoll JB, Chen CP, Grote RR, Souhan B, Dadap JI, Stein A, Lu M, Bergman K, Osgood RM. A 60 Gb/s MDM-WDM Si photonic link with < 0.7 dB power penalty per channel. Opt Express 2014; 22:18543-18555. [PMID: 25089474 DOI: 10.1364/oe.22.018543] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Mode-division-multiplexing (MDM) and wavelength-division-multiplexing (WDM) are employed simultaneously in a multimode silicon waveguide to realize on-chip MDM and MDM-WDM transmission. Asymmetric Y-junction MDM multiplexers and demultiplexers are utilized for low coherently suppressed demultiplexed crosstalk at the receiver. We demonstrate aggregate bandwidths of 20 Gb/s and 60 Gb/s for MDM and MDM-WDM on-chip links, respectively, with measured 10(-9) BER power penalties between 0.1 dB and 0.7 dB per channel.
Collapse
|
17
|
Dadap JI, Karlsson M, Panoiu NC. Focus issue introduction: nonlinear optics 2013. Opt Express 2013; 21:31176-31178. [PMID: 24514691 DOI: 10.1364/oe.21.031176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Nonlinear Optics has continued to develop over the last few years at an extremely fast pace, with significant advances being reported in nonlinear optical metamaterials, optical signal processing, quantum optics, nonlinear optics at subwavelength scale, and biophotonics. These exciting new developments have generated significant potential for a broad spectrum of technological applications in which nonlinear-optical processes play a central role.
Collapse
|
18
|
Jin W, Yeh PC, Zaki N, Zhang D, Sadowski JT, Al-Mahboob A, van der Zande AM, Chenet DA, Dadap JI, Herman IP, Sutter P, Hone J, Osgood RM. Direct measurement of the thickness-dependent electronic band structure of MoS2 using angle-resolved photoemission spectroscopy. Phys Rev Lett 2013; 111:106801. [PMID: 25166690 DOI: 10.1103/physrevlett.111.106801] [Citation(s) in RCA: 150] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Indexed: 06/03/2023]
Abstract
We report on the evolution of the thickness-dependent electronic band structure of the two-dimensional layered-dichalcogenide molybdenum disulfide (MoS2). Micrometer-scale angle-resolved photoemission spectroscopy of mechanically exfoliated and chemical-vapor-deposition-grown crystals provides direct evidence for the shifting of the valence band maximum from Γ to K, for the case of MoS2 having more than one layer, to the case of single-layer MoS2, as predicted by density functional theory. This evolution of the electronic structure from bulk to few-layer to monolayer MoS2 had earlier been predicted to arise from quantum confinement. Furthermore, one of the consequences of this progression in the electronic structure is the dramatic increase in the hole effective mass, in going from bulk to monolayer MoS2 at its Brillouin zone center, which is known as the cause for the decreased carrier mobility of the monolayer form compared to that of bulk MoS2.
Collapse
Affiliation(s)
- Wencan Jin
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA
| | - Po-Chun Yeh
- Department of Electrical Engineering, Columbia University, New York, New York 10027, USA
| | - Nader Zaki
- Department of Electrical Engineering, Columbia University, New York, New York 10027, USA
| | - Datong Zhang
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA
| | - Jerzy T Sadowski
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Abdullah Al-Mahboob
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - Arend M van der Zande
- Energy Frontier Research Center, Columbia University, New York, New York 10027, USA and Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA
| | - Daniel A Chenet
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA
| | - Jerry I Dadap
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA
| | - Irving P Herman
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA
| | - Peter Sutter
- Center for Functional Nanomaterials, Brookhaven National Laboratory, Upton, New York 11973, USA
| | - James Hone
- Department of Mechanical Engineering, Columbia University, New York, New York 10027, USA
| | - Richard M Osgood
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027, USA and Department of Electrical Engineering, Columbia University, New York, New York 10027, USA
| |
Collapse
|
19
|
Driscoll JB, Grote RR, Souhan B, Dadap JI, Lu M, Osgood RM. Asymmetric Y junctions in silicon waveguides for on-chip mode-division multiplexing. Opt Lett 2013; 38:1854-6. [PMID: 23722767 DOI: 10.1364/ol.38.001854] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Silicon waveguide asymmetric Y junction mode multiplexers and demultiplexers are demonstrated for applications in on-chip mode-division multiplexing (MDM). We measure demultiplexed crosstalk as low as -30 dB, <-9 dB over the C band, and insertion loss <1.5 dB for multimode links up to 1.2 mm in length. The frequency response of these devices is shown to depend upon Y junction angle and multimode interconnect length. Interference effects are shown to be advantageous for low-crosstalk MDM, even while using compact Y junctions designed to be outside the mode-sorting regime.
Collapse
Affiliation(s)
- Jeffrey B Driscoll
- Microelectronics Sciences Laboratories, Columbia University, New York, New York 10027, USA.
| | | | | | | | | | | |
Collapse
|
20
|
Hong SY, Yeh PC, Dadap JI, Osgood RM. Interfacial dipole formation and surface-electron confinement in low-coverage self-assembled thiol layers: thiophenol and p-fluorothiophenol on Cu(111). ACS Nano 2012. [PMID: 23181602 DOI: 10.1021/nn303715d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Model systems of organic self-assembled monolayers are important in achieving full atomic-scale understanding of molecular-electronic interfaces as well as the details of their charge transfer physics. Here we use two-photon photoemission to measure the evolving unoccupied and occupied interfacial electronic structure of two thiolate species, thiophenol and p-fluorothiophenol, adsorbed on Cu(111) as a function of molecular coverage. Our measurements focus on the role of adsorbates in shifting surface polarization and effecting surface electron confinement. As the coverage of each molecule increases, their photoemission-measured work functions exhibit nearly identical behavior up to 0.4-0.5 ML, at which point their behavior diverges; this behavior can be fit to an interfacial bond model for the surface dipole. In addition, our results show the emergence of an interfacial electronic state 0.1-0.2 eV below the Fermi level. This electronic state is attributed to quantum-mechanical-confinement shifting of the Cu(111) surface state by the molecular adsorbates.
Collapse
Affiliation(s)
- Sung-Young Hong
- Department of Chemistry, Columbia University, New York, New York 10027, USA
| | | | | | | |
Collapse
|
21
|
Driscoll JB, Ophir N, Grote RR, Dadap JI, Panoiu NC, Bergman K, Osgood RM. Width-modulation of Si photonic wires for quasi-phase-matching of four-wave-mixing: experimental and theoretical demonstration. Opt Express 2012; 20:9227-9242. [PMID: 22513635 DOI: 10.1364/oe.20.009227] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We experimentally demonstrate quasi-phase-matched (QPM) four-wave-mixing (FWM) in silicon (Si) nanowire waveguides with sinusoidally modulated width. We perform discrete wavelength conversion over 250 nm, and observe 12 dB conversion efficiency (CE) enhancement for targeted wavelengths more than 100 nm away from the edge of the 3-dB conversion bandwidth. The QPM process in Si nanowires is rigorously modeled, with results explaining experimental observations. The model is further used to investigate the dependence of the CE on key device parameters, and to introduce devices that facilitate wavelength conversion between the C-band and mid-IR. Devices based on a superposition of sinusoidal gratings are investigated theoretically, and are shown to provide CE enhancement over the entire C-band. Width-modulation is further shown to be compatible with zero-dispersion-wavelength pumping for broadband wavelength conversion. The results indicate that QPM via width-modulation is an effective technique for extending the spectral domain of efficient FWM in Si waveguides.
Collapse
Affiliation(s)
- Jeffrey B Driscoll
- Microelectronics Sciences Laboratories, Columbia University, New York, NY 10027, USA.
| | | | | | | | | | | | | |
Collapse
|
22
|
Driscoll JB, Grote RR, Liu X, Dadap JI, Panoiu NC, Osgood RM. Directionally anisotropic Si nanowires: on-chip nonlinear grating devices in uniform waveguides. Opt Lett 2011; 36:1416-1418. [PMID: 21499375 DOI: 10.1364/ol.36.001416] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Computational studies are used to show that the crystalline structure of Si causes the waveguide Kerr effective nonlinearity, γ, to vary by 10% for in-plane variation of the orientation of a silicon nanowire waveguide (SiNWG) fabricated on a standard silicon-on-insulator wafer. Our analysis shows that this angular dependence of γ can be employed to form a nonlinear Kerr grating in dimensionally uniform SiNWGs based on either ring resonators or cascaded waveguide bends. The magnitude of the nonlinear index variation in these gratings is found to be sufficient for phase matching in four-wave mixing and other optical parametric processes.
Collapse
Affiliation(s)
- Jeffrey B Driscoll
- Microelectronics Sciences Laboratories, Columbia University, New York, New York 10027, USA.
| | | | | | | | | | | |
Collapse
|
23
|
Liu X, Driscoll JB, Dadap JI, Osgood RM, Assefa S, Vlasov YA, Green WMJ. Self-phase modulation and nonlinear loss in silicon nanophotonic wires near the mid-infrared two-photon absorption edge. Opt Express 2011; 19:7778-7789. [PMID: 21503088 DOI: 10.1364/oe.19.007778] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We report an experimental study of picosecond pulse propagation through a 4-mm-long Si nanophotonic wire with normal dispersion, at excitation wavelengths from 1775 to 2250 nm. This wavelength range crosses the mid-infrared two-photon absorption edge of Si at ~2200 nm. Significant reduction in nonlinear loss due to two-photon absorption is measured as excitation wavelengths approach 2200 nm. At high input power, self-phase modulation is clearly demonstrated by the development of power-dependant spectral fringes. Asymmetry and blue-shift in the appearance of the spectral fringes at 1775 nm versus 2200 nm is further shown to originate from a strong reduction in the intra-pulse density of two-photon absorption-generated free carriers and the associated free-carrier dispersion. Analysis of experimental data and comparison with numerical simulations illustrates that the two-photon absorption coefficient β(TPA) obtained here from nanophotonic wire measurements is in reasonable agreement with prior measurements of bulk silicon crystals, and that bulk Si values of the nonlinear refractive index n(2) can be confidently incorporated in the modeling of pulse propagation in deeply-scaled waveguide structures.
Collapse
Affiliation(s)
- Xiaoping Liu
- Department of Electrical Engineering, Columbia University, 1300 S. W. Mudd Building, 500 W. 120th Street, New York, NY 10027, USA.
| | | | | | | | | | | | | |
Collapse
|
24
|
Hao Z, Dadap JI, Knox KR, Yilmaz MB, Zaki N, Johnson PD, Osgood RM. Nonequilibrium band mapping of unoccupied bulk states below the vacuum level by two-photon photoemission. Phys Rev Lett 2010; 105:017602. [PMID: 20867478 DOI: 10.1103/physrevlett.105.017602] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Indexed: 05/29/2023]
Abstract
We demonstrate angle-resolved, tunable, two-photon photoemission (2PPE) to map a bulk unoccupied band, viz. the Cu sp band 0 to 1 eV below the vacuum level, in the vicinity of the L point. This short-lived bulk band is seen due to the strong optical pump rate, and the observed transition energies and their dispersion with photon energy ℏω, are in excellent agreement with tight-binding band-structure calculations. The variation of the final-state energy with ℏω has a measured slope of ∼1.64 in contrast to values of 1 or 2 observed for 2PPE from two-dimensional states. This unique variation illustrates the significant role of the perpendicular momentum ℏk_{⊥} in 2PPE.
Collapse
Affiliation(s)
- Zhaofeng Hao
- Center for Integrated Science and Engineering, Columbia University, New York, New York 10027, USA
| | | | | | | | | | | | | |
Collapse
|
25
|
Astar W, Driscoll JB, Liu X, Dadap JI, Green WMJ, Vlasov YA, Carter GM, Osgood RM. Conversion of 10 Gb/s NRZ-OOK to RZ-OOK utilizing XPM in a Si nanowire. Opt Express 2009; 17:12987-12999. [PMID: 19654703 DOI: 10.1364/oe.17.012987] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have demonstrated for the first time to our knowledge, the conversion of 10 Gb/s non-return-to-zero (NRZ) on-off keying (NRZ-OOK) to RZ-OOK using cross-phase modulation (XPM) in a compact, Silicon (Si) nanowire and a detuned filter. The pulse format conversion resulted in a polarity-preserved, correctly-coded RZ-OOK signal, with no evidence of an error-floor for BER < 10(-11). The advantages of a passive Si nanowire can lead to a compact, power-efficient, highly simplified configuration, amenable to chip-level integration.
Collapse
Affiliation(s)
- W Astar
- The Laboratory for Physical Sciences, 8050 Greenmead Drive, College Park, MD 20740, USA
| | | | | | | | | | | | | | | |
Collapse
|
26
|
|
27
|
Shan J, Dadap JI, Heinz TF. Circularly polarized light in the single-cycle limit: The nature of highly polychromatic radiation of defined polarization. Opt Express 2009; 17:7431-7439. [PMID: 19399121 DOI: 10.1364/oe.17.007431] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have developed a general analytic description of polarized light pulses and explored the properties of circularly polarized single-cycle pulses. The temporal evolution of the electric-field vector of such spectrally broad pulses, which may be described in terms of a Hilbert transform relationship, differs significantly from the well-known behavior of quasi-monochromatic radiation. Single-cycle circularly polarized pulses are produced and characterized experimentally in the terahertz spectral region.
Collapse
Affiliation(s)
- Jie Shan
- Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106, USA.
| | | | | |
Collapse
|
28
|
Driscoll JB, Liu X, Yasseri S, Hsieh I, Dadap JI, Osgood RM. Large longitudinal electric fields (Ez) in silicon nanowire waveguides. Opt Express 2009; 17:2797-2804. [PMID: 19219184 DOI: 10.1364/oe.17.002797] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We demonstrate the presence of strong longitudinal electric fields (E(z)) in silicon nanowire waveguides through numerical computation. These waveguide fields can be engineered through choice of waveguide geometry to exhibit amplitudes as high as 97% that of the dominant transverse field component. We show even larger longitudinal fields created in free space by a terminated waveguide can become the dominant electric field component, and demonstrate E(z) has a large effect on waveguide nonlinearity. We discuss the possibility of controlling the strength and symmetry of E(z) using a dual waveguide design, and show that the resulting longitudinal field is sharply peaked beyond the diffraction limit.
Collapse
Affiliation(s)
- Jeffrey B Driscoll
- Department of Electrical Engineering, Columbia University, 1300 S. W. Mudd Building, 500 W. 120th Street, New York, New York 10027, USA.
| | | | | | | | | | | |
Collapse
|
29
|
Liu X, Green WMJ, Chen X, Hsieh IW, Dadap JI, Vlasov YA, Osgood RM. Conformal dielectric overlayers for engineering dispersion and effective nonlinearity of silicon nanophotonic wires. Opt Lett 2008; 33:2889-2891. [PMID: 19079482 DOI: 10.1364/ol.33.002889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We introduce and study numerically a method for dispersion engineering of Si nanophotonic wires using a thin conformal silicon nitride film deposited around the Si core. Simulations show that this approach may be used to achieve the dispersion characteristics required for broadband, phase-matched, four-wave mixing processes, while simultaneously maintaining strong modal confinement within the Si core for high effective nonlinearity.
Collapse
Affiliation(s)
- Xiaoping Liu
- Microelectronics Sciences Laboratories, Columbia University, New York, NY 10027, USA.
| | | | | | | | | | | | | |
Collapse
|
30
|
Dadap JI, Panoiu NC, Chen X, Hsieh IW, Liu X, Chou CY, Dulkeith E, McNab SJ, Xia F, Green WMJ, Sekaric L, Vlasov YA, Osgood RM. Nonlinear-optical phase modification in dispersion-engineered Si photonic wires. Opt Express 2008; 16:1280-1299. [PMID: 18542202 DOI: 10.1364/oe.16.001280] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The strong dispersion and large third-order nonlinearity in Si photonic wires are intimately linked in the optical physics needed for the optical control of phase. By carefully choosing the waveguide dimensions, both linear and nonlinear optical properties of Si wires can be engineered. In this paper we provide a review of the control of phase using nonlinear-optical effects such as self-phase and cross-phase modulation in dispersion-engineered Si wires. The low threshold powers for phase-changing effects in Si-wires make them potential candidates for functional nonlinear optical devices of just a few millimeters in length.
Collapse
Affiliation(s)
- J I Dadap
- Microelectronics Sciences Laboratories, Columbia University, New York, NY 10027, USA.
| | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
31
|
Roth RM, Panoiu NC, Adams MM, Dadap JI, Osgood RM. Polarization-tunable plasmon-enhanced extraordinary transmission through metallic films using asymmetric cruciform apertures. Opt Lett 2007; 32:3414-3416. [PMID: 18059951 DOI: 10.1364/ol.32.003414] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Plasmon-enhanced transmission of light incident on a periodic array of nanoscale, asymmetric cruciform patterns is demonstrated. The corresponding transmission spectra are shown to be polarization dependent and possess unique properties, such as the existence of isosbestic points for which the transmission is polarization insensitive. Transmission peaks corresponding to localized surface plasmon resonances and extended surface plasmons are also identified.
Collapse
Affiliation(s)
- Ryan M Roth
- Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY 10027, USA.
| | | | | | | | | |
Collapse
|
32
|
Hsieh IW, Chen X, Liu X, Dadap JI, Panoiu NC, Chou CY, Xia F, Green WM, Vlasov YA, Osgood RM. Supercontinuum generation in silicon photonic wires. Opt Express 2007; 15:15242-15249. [PMID: 19550808 DOI: 10.1364/oe.15.015242] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We observe spectral broadening of more than 350 nm, i.e., a 3/10-octave span, upon propagation of ultrashort 1.3-mum-wavelength optical pulses in a 4.7-mm-long silicon-photonic-wire waveguide. We measure the wavelength dependence of the spectral features and relate it to waveguide dispersion and input power. The spectral characteristics of the output pulses are shown to be consistent, in part, with higher-order soliton radiative effects.
Collapse
|
33
|
Hsieh IW, Chen X, Dadap JI, Panoiu NC, Osgood RM, McNab SJ, Vlasov YA. Cross-phase modulation-induced spectral and temporal effects on co-propagating femtosecond pulses in silicon photonic wires. Opt Express 2007; 15:1135-1146. [PMID: 19532341 DOI: 10.1364/oe.15.001135] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
By performing time-resolved experiments and power-dependent measurements using femtosecond pulses inside submicron cross-section Si photonic-wire waveguides, we demonstrate strong cross-phase modulation (XPM) effects. We find that XPM in Si wires can be significant even for low peak pump powers, i.e., ~15 mW for pi phase shift. Our experimental data closely match numerical simulations using a rigorous coupled-wave theoretical treatment. Our results suggest that XPM is a potentially useful approach for all-optical control of photonic devices in Si wires.
Collapse
|
34
|
Hsieh IW, Chen X, Dadap JI, Panoiu NC, Osgood RM, McNab SJ, Vlasov YA. Ultrafast-pulse self-phase modulation and third-order dispersion in Si photonic wire-waveguides. Opt Express 2006; 14:12380-12387. [PMID: 19529669 DOI: 10.1364/oe.14.012380] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
By propagating femtosecond pulses inside submicron-crosssection Si photonic-wire waveguides with anomalous dispersion, we demonstrate that the pulse-propagation dynamics is strongly influenced by the combined action of optical nonlinearity and up to third-order dispersion with minimal carrier effects. Because of strong light confinement, a nonlinear phase shift of a few pi due to self-phase modulation is observed at a pulse peak-power of just ~250 mW. We also observe soliton-emitted radiation, fully supported by theoretical analysis, from which we determine directly the third-order dispersion coefficient, beta(3) = -0.73 +/- 0.05 ps(3)/m at 1537 nm.
Collapse
|
35
|
Abstract
We report spontaneous Raman scattering at 1550 nm in ultrasmall silicon-on-insulator (SOI) strip waveguides of 0.098-microm2 cross-sectional area. The submicrometer-scale dimensions provide tight optical confinement and, hence, highly efficient Raman scattering with milliwatt-level cw pump powers. The prospect of Raman amplification in such a deeply scaled-down waveguide device in the presence of various loss mechanisms, particularly free-carrier loss that arises from two-photon absorption, is discussed, and the feasibility of high-gain SOI-based fully integrated optical amplifiers is shown.
Collapse
Affiliation(s)
- Jerry I Dadap
- Microelectronics Sciences Laboratories, Columbia University, New York, New York 10027, USA.
| | | | | | | | | |
Collapse
|
36
|
Dadap JI, Shan J, Weling AS, Misewich JA, Nahata A, Heinz TF. Measurement of the vector character of electric fields by optical second-harmonic generation. Opt Lett 1999; 24:1059-1061. [PMID: 18073940 DOI: 10.1364/ol.24.001059] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We present a scheme for the determination of the vector nature of an electric field by optical second-harmonic generation. We demonstrate the technique by mapping the two-dimensional electric-field vector of a biased transmission line structure on silicon with a spatial resolution of ~10mum .
Collapse
|
37
|
|
38
|
Dadap JI, Wilson PT, Anderson MH, Downer MC, Ter Beek M. Femtosecond carrier-induced screening of dc electric-field-induced second-harmonic generation at the Si(001) SiO(2) interface. Opt Lett 1997; 22:901-903. [PMID: 18185700 DOI: 10.1364/ol.22.000901] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Carrier-induced screening of the dc electric field at the Si(001)-SiO(2) interface is observed by intensity-dependent and femtosecond-time-resolved second-harmonic spectroscopy. The screening occurs on a time scale of ~?(p)(-1) , the reciprocal plasma frequency of the generated carriers.
Collapse
|
39
|
Dadap JI, Hu XF, Anderson MH, Downer MC, Lowell JK, Aktsipetrov OA. Optical second-harmonic electroreflectance spectroscopy of a Si(001) metal-oxide-semiconductor structure. Phys Rev B Condens Matter 1996; 53:R7607-R7609. [PMID: 9982278 DOI: 10.1103/physrevb.53.r7607] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|
40
|
Dadap JI, Focht GB, Reitze DH, Downer MC. Two-photon absorption in diamond and its application to ultraviolet femtosecond pulse-width measurement. Opt Lett 1991; 16:499-501. [PMID: 19773979 DOI: 10.1364/ol.16.000499] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Intensity-dependent transmission measurements of 310-nm femtosecond pulses show that diamond has a twophoton absorption coefficient of 0.75 +/- 0.15 cm/GW, in approximate agreement with universal scaling formulas for two-photon absorption in diamond-structure materials. We then demonstrate that two-photon absorption is strong enough to permit simple measurements of ultraviolet femtosecond pulse widths in single-crystal diamond plates that are thin enough (250 microm) to be both inexpensive and dispersion free. Autocorrelation measurements of 10-50-nJ, 0.18-1.4-ps pulses are presented. The method requires no phase matching and can be applied to pulses in the wavelength range of 220-550 nm.
Collapse
|
41
|
Seibert K, Cho GC, Kütt W, Kurz H, Reitze DH, Dadap JI, Ahn H, Downer MC, Malvezzi AM. Femtosecond carrier dynamics in graphite. Phys Rev B Condens Matter 1990; 42:2842-2851. [PMID: 9995773 DOI: 10.1103/physrevb.42.2842] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
|