Search

Article

x

留言板

尊敬的读者、作者、审稿人, 关于本刊的投稿、审稿、编辑和出版的任何问题, 您可以本页添加留言。我们将尽快给您答复。谢谢您的支持!

姓名
邮箱
手机号码
标题
留言内容
验证码

Infrared spectroscopic study of topological material BaMnSb2

Qiu Zi-Yang Chen Yan Qiu Xiang-Gang

Citation:

Infrared spectroscopic study of topological material BaMnSb2

Qiu Zi-Yang, Chen Yan, Qiu Xiang-Gang
PDF
HTML
Get Citation
  • A detailed infrared optical spectrum of the new topological material BaMnSb2 has been measured at temperatures ranging from 7 K to 295 K. As the temperature decreases, the plasma minimum has a clear blue shift in reflectivity spectrum, indicating that the carrier density changes with temperature. In the real part of the optical conductivity $\sigma_{1}(\omega)$, two linearly-increased components can be identified, but neither of their extrapolation pass through the origin, which proves that BaMnSb2 has a gapped Dirac dispersion near the Fermi level. Comparing with the theoretical calculation by using first-principles methods, the onset of these two linearly-increased components are in good agreement with the band structures. In addition, a range of constant optical conductivity is found in $\sigma_{1}(\omega)$, which cannot be described well by the Drude-Lorentz model. Therefore, we introduce a frequency-independent component to fit $\sigma_{1}(\omega)$ successfully. However, different from the Dirac nodal-line semimetal YbMnSb2 which shares same fitting results as well as crystal structure, the constant component in BaMnSb2 has a small proportion of $\sigma_{1}(\omega)$. Through calculation and analysis, we attribute the constant component to the surface state of BaMnSb2.
      Corresponding author: Qiu Xiang-Gang, xgqiu@iphy.ac.cn
    [1]

    Dziawa P, Kowalski B J, Dybko K, Buczko R, Szczerbakow A, Szot M, Lusakowska E, Balasubra- manian T, Wojek B M, Berntsen M H 2012 Nat. Mater. 11 1023Google Scholar

    [2]

    Zhang H, Liu C X, Qi X L, Dai X, Fang Z, Zhang S C 2009 Nat. Phys. 5 438Google Scholar

    [3]

    Wang Z J, Sun Y, Chen X Q, Franchini C, Xu G, Weng H M, Dai X, Fang Z 2012 Phys. Rev. B 85 195320Google Scholar

    [4]

    Ma X M, Zhao Y, Zhang K, Kumar S, Lu R, Li J, Yao Q, Shao J, Hou F, Wu X 2021 Phys. Rev. B 103 121112Google Scholar

    [5]

    de Boer J C, Wielens D H, Voerman J A, de Ronde B, Huang Y, Golden M S, Li C, Brinkman A 2019 Phys. Rev. B 99 085124Google Scholar

    [6]

    Hsieh D, Xia Y, Qian D, Wray L, Meier F, Dil J H, Osterwalder J, Patthey L, Fedorov A V, Lin H 2009 Phys. Rev. Lett. 103 146401Google Scholar

    [7]

    Su Y H, Shi W, Felser C, Sun Y 2018 Phys. Rev. B 97 155431Google Scholar

    [8]

    Singh S, Garcia-Castro A C, Valencia-Jaime I, Munoz F, Romero A H 2016 Phys. Rev. B 94 161116Google Scholar

    [9]

    Bansil A, Lin H, Das T 2016 Rev. Mod. Phys. 88 021004Google Scholar

    [10]

    Hasan M Z, Kane C L 2010 Rev. Mod. Phys. 82 3045Google Scholar

    [11]

    Qi X L, Zhang S C 2011 Rev. Mod. Phys. 83 1057Google Scholar

    [12]

    Park J, Lee G, Wolff-Fabris F, Koh Y Y, Eom M J, Kim Y K, Farhan M A, Jo Y J, Kim C, Shim J H 2011 Phys. Rev. Lett. 107 126402Google Scholar

    [13]

    Wang K F, Graf D, Wang L M, Lei H C, Tozer S W, Petrovic C 2012 Phys. Rev. B 85 041101

    [14]

    Li L J, Wang K F, Graf D, Wang L M, Wang A F, Petrovic C 2016 Phys. Rev. B 93 115141Google Scholar

    [15]

    Wang A F, Zaliznyak I, Ren W J, Wu L J, Graf D, Garlea V O, Warren J B, Bozin E, Zhu Y M, Petrovic C 2016 Phys. Rev. B 94 165161Google Scholar

    [16]

    Wang K F, Graf D, Lei H C, Tozer S W, Petrovic C 2011 Phys. Rev. B 84 220401Google Scholar

    [17]

    May A F, McGuire M A, Sales B C 2014 Phys. Rev. B 90 075109Google Scholar

    [18]

    Chinotti M, Pal A, Ren W J, Petrovic C, Degiorgi L 2016 Phys. Rev. B 94 245101Google Scholar

    [19]

    Lee G, Farhan M A, Kim J S, Shim J H 2013 Phys. Rev. B 87 245104Google Scholar

    [20]

    Liu J, Hu J, Cao H, Zhu Y, Chuang A, Graf D, Adams D J, Radmanesh S M A, Spinu L, Chiorescu I 2016 Sci. Rep. 6 30525Google Scholar

    [21]

    Chaudhuri D, Cheng B, Yaresko A, Gibson Q D, Cava R J, Armitage N P 2017 Phys. Rev. B 96 075151Google Scholar

    [22]

    Qiu Z Y, Le C C, Dai Y M, Xu B, He J B, Yang R, Chen G F, Hu J P, Qiu X G 2018 Phys. Rev. B 98 115151Google Scholar

    [23]

    Kealhofer R, Jang S, Griffin S M, John C, Benavides K A, Doyle S, Helm T, Moll P J W, Neaton J B, Chan J Y 2018 Phys. Rev. B 97 045109Google Scholar

    [24]

    Wang Y Y, Xu S, Sun L L, Xia T L 2018 Phys. Rev. Mater. 2 021201Google Scholar

    [25]

    Qiu Z Y, Le C C, Liao Z Y, Xu B, Yang R, Hu J P, Dai Y M, Qiu X G 2019 Phys. Rev. B 100 125136Google Scholar

    [26]

    Qiu Z Y, Liao Z Y, Qiu X G 2019 Chin. Phys. B 28 047801Google Scholar

    [27]

    Farhan M A, Lee G, Shim J H 2014 J. Phys. Condens. Matter 26 042201Google Scholar

    [28]

    Rong H T, Zhou L Q, He J B, Song C Y, Xu Y, Cai Y Q, Li C, Wang Q Y, Zhao L, Liu G D, Xu Z Y, Chen G F, Weng H M, Zhou X J 2021 Chin. Phys. B 30 067403Google Scholar

    [29]

    Armitage N P, Mele E J, Vishwanath A 2018 Rev. Mod. Phys. 90

    [30]

    Carbotte J P 2017 J. Phys. Condens. Matter 29 045301Google Scholar

    [31]

    Hosur P, Parameswaran S A, Vishwanath A 2012 Phys. Rev. Lett. 108 046602Google Scholar

    [32]

    Schilling M B, Schoop L M, Lotsch B V, Dressel M, Pronin A V 2017 Phys. Rev. Lett. 119 187401Google Scholar

    [33]

    Topp A, Queiroz R, Grüneis A, Müchler L, Rost A W, Varykhalov A, Marchenko D, Krivenkov M, Rodolakis F, McChesney J L 2017 Phys. Rev. X 7 041073

    [34]

    Chen R Y, Zhang S J, Zhang M Y, Dong T, Wang N L 2017 Phys. Rev. Lett. 118 107402Google Scholar

    [35]

    Shao Y, Sun Z, Wang Y, Xu C, Sankar R, Breindel A J, Cao C, Fogler M M, Millis A J, Chou F 2019 Proc. Natl. Acad. Sci. 11v 1168

    [36]

    Homes C C, Reedyk M, Cradles D A, Timusk T 1993 Appl. Opt. 32 2976Google Scholar

    [37]

    Li B W, Jiang W C, Chen G Y, Xiang Y, Xie W, Dai Y M, Zhu X Y, Yang H, Wen H H 2020 Sci. China-Phys. Mech. Astron. 63 117011Google Scholar

    [38]

    Kuzmenko A B, van Heumen E, Carbone F, van der Marel D 2008 Phys. Rev. Lett. 100 117401Google Scholar

    [39]

    Mak K F, Sfeir M Y, Wu Y, Lui C H, Misewich J A, Heinz T F 2008 Phys. Rev. Lett. 101 196405Google Scholar

    [40]

    Ando T, Zheng Y, Suzuura H 2002 J. Phys. Soc. Jpn. 71 1318Google Scholar

    [41]

    Habe T, Koshino M 2018 Phys. Rev. B 98 125201Google Scholar

  • 图 1  BaMnSb2在5个温度点50—3000 cm–1范围内的反射率. 插图为室温下到30000 cm–1的反射谱

    Figure 1.  Reflectivity of BaMnSb2 at five representative temperatures between 50–3000 cm–1. The inset displays the reflectivity up to 30000 cm–1 at room temperature

    图 2  通过Kramers-Kronig计算得到相应的光电导的实部. 插图为室温下到更高频率的光电导谱

    Figure 2.  The corresponding real part of optical conductivity $ \sigma_{1}(\omega) $ is calculated through Kramers-Kronig transformation. The inset shows $ \sigma_{1}(\omega) $ over a broad frequency range at room temperature

    图 3  蓝色实线为7 K时BaMnSb2在高频波段的光电导谱, 粉色虚线和黑色虚线分别示意了两段线性增加的光电导. 插图是不同温度下粉色虚线线性外延与横坐标的交点, 对应了Dirac能隙随温度变化的关系

    Figure 3.  The blue solid curve is $ \sigma_{1}(\omega) $ for BaMnSb2 at 7 K in high-frequency range. The pink and dark dashed lines denote two range of linearly-increased $ \sigma_{1}(\omega) $. The inset exhibits extrapolation of the pink dashed line to zero conductivity at finite frequency, corresponding to the temperature-dependent Dirac gap

    图 4  BaMnSb2在7 K时的$ \sigma_{1}(\omega) $, 其中黑色虚线注明了恒定光电导组分. 插图为$ \sigma_{1}(\omega) $的谱重随频率变化的关系, 其中黑色虚线表明在350—1150 cm–1范围内谱重随频率线性增加

    Figure 4.  $ \sigma_{1}(\omega) $ for BaMnSb2 at 7 K. The dark dashed line denotes the frequency-independent component. The inset portrays the spectral weight $ S(\omega) $ at 7 K, and the dark dashed line represents $ S(\omega) $ follows an ω behavior in the range between 350–1150 cm–1

    图 5  $ \sigma_{1}(\omega) $在0—2500 cm–1范围内的拟合结果, 拟合的组分为一个绿色的Drude 分量, 一个粉色的Lorentz分量, 和一个深黄色的恒定分量. 对于100和200 cm–1附近的红外活性声子暂不讨论

    Figure 5.  Fitting results for $ \sigma_{1}(\omega) $ in 0–2500 cm–1 frequency range, which is decomposed into one Drude term (green dashed line), one Lorentz term (pink dashed line), and a constant component (dark yellow dashed line). The infrared-active phonons near 100 and 200 cm–1 are ignored

    Baidu
  • [1]

    Dziawa P, Kowalski B J, Dybko K, Buczko R, Szczerbakow A, Szot M, Lusakowska E, Balasubra- manian T, Wojek B M, Berntsen M H 2012 Nat. Mater. 11 1023Google Scholar

    [2]

    Zhang H, Liu C X, Qi X L, Dai X, Fang Z, Zhang S C 2009 Nat. Phys. 5 438Google Scholar

    [3]

    Wang Z J, Sun Y, Chen X Q, Franchini C, Xu G, Weng H M, Dai X, Fang Z 2012 Phys. Rev. B 85 195320Google Scholar

    [4]

    Ma X M, Zhao Y, Zhang K, Kumar S, Lu R, Li J, Yao Q, Shao J, Hou F, Wu X 2021 Phys. Rev. B 103 121112Google Scholar

    [5]

    de Boer J C, Wielens D H, Voerman J A, de Ronde B, Huang Y, Golden M S, Li C, Brinkman A 2019 Phys. Rev. B 99 085124Google Scholar

    [6]

    Hsieh D, Xia Y, Qian D, Wray L, Meier F, Dil J H, Osterwalder J, Patthey L, Fedorov A V, Lin H 2009 Phys. Rev. Lett. 103 146401Google Scholar

    [7]

    Su Y H, Shi W, Felser C, Sun Y 2018 Phys. Rev. B 97 155431Google Scholar

    [8]

    Singh S, Garcia-Castro A C, Valencia-Jaime I, Munoz F, Romero A H 2016 Phys. Rev. B 94 161116Google Scholar

    [9]

    Bansil A, Lin H, Das T 2016 Rev. Mod. Phys. 88 021004Google Scholar

    [10]

    Hasan M Z, Kane C L 2010 Rev. Mod. Phys. 82 3045Google Scholar

    [11]

    Qi X L, Zhang S C 2011 Rev. Mod. Phys. 83 1057Google Scholar

    [12]

    Park J, Lee G, Wolff-Fabris F, Koh Y Y, Eom M J, Kim Y K, Farhan M A, Jo Y J, Kim C, Shim J H 2011 Phys. Rev. Lett. 107 126402Google Scholar

    [13]

    Wang K F, Graf D, Wang L M, Lei H C, Tozer S W, Petrovic C 2012 Phys. Rev. B 85 041101

    [14]

    Li L J, Wang K F, Graf D, Wang L M, Wang A F, Petrovic C 2016 Phys. Rev. B 93 115141Google Scholar

    [15]

    Wang A F, Zaliznyak I, Ren W J, Wu L J, Graf D, Garlea V O, Warren J B, Bozin E, Zhu Y M, Petrovic C 2016 Phys. Rev. B 94 165161Google Scholar

    [16]

    Wang K F, Graf D, Lei H C, Tozer S W, Petrovic C 2011 Phys. Rev. B 84 220401Google Scholar

    [17]

    May A F, McGuire M A, Sales B C 2014 Phys. Rev. B 90 075109Google Scholar

    [18]

    Chinotti M, Pal A, Ren W J, Petrovic C, Degiorgi L 2016 Phys. Rev. B 94 245101Google Scholar

    [19]

    Lee G, Farhan M A, Kim J S, Shim J H 2013 Phys. Rev. B 87 245104Google Scholar

    [20]

    Liu J, Hu J, Cao H, Zhu Y, Chuang A, Graf D, Adams D J, Radmanesh S M A, Spinu L, Chiorescu I 2016 Sci. Rep. 6 30525Google Scholar

    [21]

    Chaudhuri D, Cheng B, Yaresko A, Gibson Q D, Cava R J, Armitage N P 2017 Phys. Rev. B 96 075151Google Scholar

    [22]

    Qiu Z Y, Le C C, Dai Y M, Xu B, He J B, Yang R, Chen G F, Hu J P, Qiu X G 2018 Phys. Rev. B 98 115151Google Scholar

    [23]

    Kealhofer R, Jang S, Griffin S M, John C, Benavides K A, Doyle S, Helm T, Moll P J W, Neaton J B, Chan J Y 2018 Phys. Rev. B 97 045109Google Scholar

    [24]

    Wang Y Y, Xu S, Sun L L, Xia T L 2018 Phys. Rev. Mater. 2 021201Google Scholar

    [25]

    Qiu Z Y, Le C C, Liao Z Y, Xu B, Yang R, Hu J P, Dai Y M, Qiu X G 2019 Phys. Rev. B 100 125136Google Scholar

    [26]

    Qiu Z Y, Liao Z Y, Qiu X G 2019 Chin. Phys. B 28 047801Google Scholar

    [27]

    Farhan M A, Lee G, Shim J H 2014 J. Phys. Condens. Matter 26 042201Google Scholar

    [28]

    Rong H T, Zhou L Q, He J B, Song C Y, Xu Y, Cai Y Q, Li C, Wang Q Y, Zhao L, Liu G D, Xu Z Y, Chen G F, Weng H M, Zhou X J 2021 Chin. Phys. B 30 067403Google Scholar

    [29]

    Armitage N P, Mele E J, Vishwanath A 2018 Rev. Mod. Phys. 90

    [30]

    Carbotte J P 2017 J. Phys. Condens. Matter 29 045301Google Scholar

    [31]

    Hosur P, Parameswaran S A, Vishwanath A 2012 Phys. Rev. Lett. 108 046602Google Scholar

    [32]

    Schilling M B, Schoop L M, Lotsch B V, Dressel M, Pronin A V 2017 Phys. Rev. Lett. 119 187401Google Scholar

    [33]

    Topp A, Queiroz R, Grüneis A, Müchler L, Rost A W, Varykhalov A, Marchenko D, Krivenkov M, Rodolakis F, McChesney J L 2017 Phys. Rev. X 7 041073

    [34]

    Chen R Y, Zhang S J, Zhang M Y, Dong T, Wang N L 2017 Phys. Rev. Lett. 118 107402Google Scholar

    [35]

    Shao Y, Sun Z, Wang Y, Xu C, Sankar R, Breindel A J, Cao C, Fogler M M, Millis A J, Chou F 2019 Proc. Natl. Acad. Sci. 11v 1168

    [36]

    Homes C C, Reedyk M, Cradles D A, Timusk T 1993 Appl. Opt. 32 2976Google Scholar

    [37]

    Li B W, Jiang W C, Chen G Y, Xiang Y, Xie W, Dai Y M, Zhu X Y, Yang H, Wen H H 2020 Sci. China-Phys. Mech. Astron. 63 117011Google Scholar

    [38]

    Kuzmenko A B, van Heumen E, Carbone F, van der Marel D 2008 Phys. Rev. Lett. 100 117401Google Scholar

    [39]

    Mak K F, Sfeir M Y, Wu Y, Lui C H, Misewich J A, Heinz T F 2008 Phys. Rev. Lett. 101 196405Google Scholar

    [40]

    Ando T, Zheng Y, Suzuura H 2002 J. Phys. Soc. Jpn. 71 1318Google Scholar

    [41]

    Habe T, Koshino M 2018 Phys. Rev. B 98 125201Google Scholar

  • [1] Jiang Long-Xing, Li Qing-Chao, Zhang Xu, Li Jing-Feng, Zhang Jing, Chen Zu-Xin, Zeng Min, Wu Hao. Spintronic devices based on topological and two-dimensional materials. Acta Physica Sinica, 2024, 73(1): 017505. doi: 10.7498/aps.73.20231166
    [2] Bao Chang-Hua, Fan Ben-Shu, Tang Pei-Zhe, Duan Wen-Hui, Zhou Shu-Yun. Floquet engineering in quantum materials. Acta Physica Sinica, 2023, 72(23): 234202. doi: 10.7498/aps.72.20231423
    [3] Ba Jia-Yan, Chen Fu-Yang, Duan Hou-Jian, Deng Ming-Xun, Wang Rui-Qiang. Planar Hall effect in topological materials. Acta Physica Sinica, 2023, 72(20): 207201. doi: 10.7498/aps.72.20230905
    [4] Wang Huan, He Chun-Juan, Xu Sheng, Wang Yi-Yan, Zeng Xiang-Yu, Lin Jun-Fa, Wang Xiao-Yan, Gong Jing, Ma Xiao-Ping, Han Kun, Wang Yi-Ting, Xia Tian-Long. Single crystal growth of topological semimetals and magnetic topological materials. Acta Physica Sinica, 2023, 72(3): 038103. doi: 10.7498/aps.72.20221574
    [5] Qiu Zi-Heng, Ahmed Yousif Ghazal, Long Jin-You, Zhang Song. Theoretical studies on molecular conformers and infrared spectra of triethylamine. Acta Physica Sinica, 2022, 71(10): 103601. doi: 10.7498/aps.71.20220123
    [6] Jiang Tian-Shu, Xiao Meng, Zhang Zhao-Qing, Chan Che-Ting. Physics and topological properties of periodic and aperiodic transmission line networks. Acta Physica Sinica, 2020, 69(15): 150301. doi: 10.7498/aps.69.20200258
    [7] Gu Kai-Yuan, Luo Tian-Chuang, Ge Jun, Wang Jian. Superconductivity in topological materials. Acta Physica Sinica, 2020, 69(2): 020301. doi: 10.7498/aps.69.20191627
    [8] Wang Shan-Shan, Wu Wei-Kang, Yang Sheng-Yuan. Progress on topological nodal line and nodal surface. Acta Physica Sinica, 2019, 68(22): 227101. doi: 10.7498/aps.68.20191538
    [9] Wu Chen-Chen, Guo Xiang-Dong, Hu Hai, Yang Xiao-Xia, Dai Qing. Graphene plasmon enhanced infrared spectroscopy. Acta Physica Sinica, 2019, 68(14): 148103. doi: 10.7498/aps.68.20190903
    [10] Xu Bing, Qiu Zi-Yang, Yang Run, Dai Yao-Min, Qiu Xiang-Gang. Optical properties of topological semimetals. Acta Physica Sinica, 2019, 68(22): 227804. doi: 10.7498/aps.68.20191510
    [11] Lin Tong, Hu Die, Shi Li-Yu, Zhang Si-Jie, Liu Yan-Qi, Lv Jia-Lin, Dong Tao, Zhao Jun, Wang Nan-Lin. Infrared spectroscopy study of ironbased superconductor Li0.8Fe0.2 ODFeSe. Acta Physica Sinica, 2018, 67(20): 207102. doi: 10.7498/aps.67.20181401
    [12] Wang An-Jing, Fang Yong-Hua, Li Da-Cheng, Cui Fang-Xiao, Wu Jun, Liu Jia-Xiang, Li Yang-Yu, Zhao Yan-Dong. Simulation of pollutant-gas-cloud infrared spectra under plane-array detecting. Acta Physica Sinica, 2017, 66(11): 114203. doi: 10.7498/aps.66.114203
    [13] Liu Jiang-Ping, Li Jun, Liu Yuan-Qiong, Lei Hai-Le, Wei Jian-Jun. Infrared absorption of deuterium molecules at low temperature. Acta Physica Sinica, 2014, 63(2): 023301. doi: 10.7498/aps.63.023301
    [14] Liu Jiang-Ping, Bi Peng, Lei Hai-Le, Li Jun, Wei Jian-Jun. Infrared absorption spectrum of solid deuterium at near-triple point temperature. Acta Physica Sinica, 2013, 62(16): 163301. doi: 10.7498/aps.62.163301
    [15] Li Xin, Yang Meng-Shi, Ye Zhi-Peng, Chen Liang, Xu Can, Chu Xiu-Xiang. DFT research on the IR spectrum of glycine tryptophan oligopeptides chain. Acta Physica Sinica, 2013, 62(15): 156103. doi: 10.7498/aps.62.156103
    [16] Sun Jie, Nie Qiu-Hua, Wang Guo-Xiang, Wang Xun-Si, Dai Shi-Xun, Zhang Wei, Song Bao-An, Shen Xiang, Xu Tie-Feng. Effect of PbI2 on optical properties of Te-based far infrared transmitting chalcogenide glasses. Acta Physica Sinica, 2011, 60(11): 114212. doi: 10.7498/aps.60.114212
    [17] Liu Xiao-Dong, Tao Wan-Jun, Hagihala Masato, Guo Qi-Xin, Meng Dong-Dong, Zhang Sen-Lin, Zheng Xu-Guang. Mid-infrared spectroscopic properties of geometrically frustrated basic cobalt chlorides. Acta Physica Sinica, 2011, 60(3): 037803. doi: 10.7498/aps.60.037803
    [18] Nie Qiu-Hua, Wang Guo-Xiang, Wang Xun-Si, Xu Tie-Feng, Dai Shi-Xun, Shen Xiang. Effect of Ga on optical properties of novel Te-based far infrared transmitting chalcogenide glasses. Acta Physica Sinica, 2010, 59(11): 7949-7955. doi: 10.7498/aps.59.7949
    [19] Bi Peng, Liu Yuan-Qiong, Tang Yong-Jian, Yang Xiang-Dong, Lei Hai-Le. Infrared absorption of liquid-hydrogen planar cryotargets. Acta Physica Sinica, 2010, 59(11): 7531-7534. doi: 10.7498/aps.59.7531
    [20] LING ZHI-HUA. STUDY OF POLARIZED FT-IR FOR ANTIFERROELECTRIC LIQUID CRYSTAL TFMHxPOCBC-D2 IN A HOMEOTROPICALLY ALIGNED CELL. Acta Physica Sinica, 2001, 50(2): 227-232. doi: 10.7498/aps.50.227
Metrics
  • Abstract views:  3927
  • PDF Downloads:  109
  • Cited By: 0
Publishing process
  • Received Date:  03 January 2022
  • Accepted Date:  28 January 2022
  • Available Online:  02 February 2022
  • Published Online:  20 May 2022

/

返回文章
返回
Baidu
map