摘要
We investigate the temperature-dependent infrared spectroscopy of SrMnSb_2, which is a semimetal with multiple Fermi surfaces. A notable blue shift of the plasma minimum in reflectivity upon cooling indicates that the carrier density varies with temperature. In the real part of the optical conductivity σ_1(ω), a linearly-increased component which extrapolates to zero conductivity at finite frequency has been identified, which suggests dispersion of gapped Dirac band structures near the Fermi level. A two-Drude model, representing two different types of carriers, is introduced to describe the real part of optical conductivity. We separate the contributions of two-Drude model in dc conductivity, and demonstrate that the transport properties of SrMnSb_2 are mainly affected by the narrow-Drude quasiparticles. Compared with the similar phenomena observed in CaMnSb_2 and SrMnBi_2, we can infer that the two-Drude model is an appropriate approach to investigate the multiband materials in AMnSb_2 and AMnBi_2 families.
We investigate the temperature-dependent infrared spectroscopy of SrMnSb_2, which is a semimetal with multiple Fermi surfaces. A notable blue shift of the plasma minimum in reflectivity upon cooling indicates that the carrier density varies with temperature. In the real part of the optical conductivity σ_1(ω), a linearly-increased component which extrapolates to zero conductivity at finite frequency has been identified, which suggests dispersion of gapped Dirac band structures near the Fermi level. A two-Drude model, representing two different types of carriers, is introduced to describe the real part of optical conductivity. We separate the contributions of two-Drude model in dc conductivity, and demonstrate that the transport properties of SrMnSb_2 are mainly affected by the narrow-Drude quasiparticles. Compared with the similar phenomena observed in CaMnSb_2 and SrMnBi_2, we can infer that the two-Drude model is an appropriate approach to investigate the multiband materials in AMnSb_2 and AMnBi_2 families.
引文
[1]Armitage N P,Mele E J and Vishwanath A 2018 Rev.Mod.Phys.90015001
[2]Bansil A,Lin H and Das T 2016 Rev.Mod.Phys.88 021004
[3]Coulter J,Sundararaman R and Narang P 2018 Phys.Rev.B 98 115130
[4]Xu N,Wang ZW,Magrez A,Bugnon P,Berger H,Matt C E,Strocov VN,Plumb N C,Radovic M and Pomjakushina E 2018 Phys.Rev.Lett.121 136401
[5]Guo Y F,Princep A J,Zhang X,Manuel P,Khalyavin D,Mazin I I,Shi Y G,Boothroyd and A T 2014 Phys.Rev.B 90 075120
[6]Wan X,Turner A M,Vishwanath A and Savrasov S Y 2011 Phys.Rev.B 83 205101
[7]Lee G,Farhan M A,Kim J S and Shim J H 2013 Phys.Rev.B 87 245104
[8]Park J,Lee G,Wolff-Fabris F,Koh Y Y,Eom M J,Kim Y K,Farhan MA,Jo Y J,Kim C and Shim J H 2011 Phys.Rev.Lett.107 126402
[9]Wang K,Graf D,Wang L,Lei H,Tozer S W and Petrovic C 2012 Phys.Rev.B 85 041101
[10]Li L,Wang K,Graf D,Wang L,Wang A and Petrovic C 2016 Phys.Rev.B 93 115141
[11]Wang A,Zaliznyak I,Ren W,Wu L,Graf D,Garlea V O,Warren J B,Bozin E,Zhu Y and Petrovic C 2016 Phys.Rev.B 94 165161
[12]Wang K,Graf D,Lei H,Tozer S W and Petrovic C 2011 Phys.Rev.B84 220401
[13]May A F,McGuire M A,Sales and B C 2014 Phys.Rev.B 90 075109
[14]Chinotti M,Pal A,Ren W J,Petrovic C and Degiorgi L 2016 Phys.Rev.B 94 245101
[15]Liu J,Hu J,Cao H,et al.2016 Sci.Rep.6 30525
[16]Chaudhuri D,Cheng B,Yaresko A,Gibson Q D,Cava R J and Armitage N P 2017 Phys.Rev.B 96 075151
[17]Qiu Z Y,Le C C,Dai Y M,Xu B,He J B,Yang R,Chen G F,Hu J Pand Qiu X G 2018 Phys.Rev.B 98 115151
[18]Wang Y Y,Xu S,Sun L L and Xia T L 2018 Phys.Rev.Materials 2021201
[19]Farhan M A,Lee G and Shim J H 2014 J.Phys.:Condens.Matter 26042201
[20]Park H J,Park B C,Lee M C,Jeong D W,Park J,Kim J S,Ji H S,Shim J H,Kim K W,Moon S J 2017 Phys.Rev.B 96 155139
[21]Park H J,Sandilands L J,You J S,Ji H S,Sohn C H,Han J W,Moon SJ,Kim K W,Shim J H and Kim J S 2016 Phys.Rev.B 93 205122
[22]Carbotte J P 2017 J.Phys.:Condens.Matter 29 045301
[23]Hosur P,Parameswaran S A and Vishwanath A 2012 Phys.Rev.Lett.108 046602
[24]Ashby P E C and Carbotte J P 2014 Phys.Rev.B 89 245121
[25]He J B,Fu Y,Zhao L X,Liang H,Chen D,Leng Y M,Wang X M,Li J,Zhang S and Xue M Q 2017 Phys.Rev.B 95 045128
[26]Homes C C,Reedyk M,Cradles D A and Timusk T 1993 Appl.Opt.322976
[27]Schilling M B,L¨ohle A,Neubauer D,Shekhar C,Felser C,Dressel Mand Pronin A V 2017 Phys.Rev.B 95 155201
[28]Beach R T and Christy R W 1997 Phys.Rev.B 16 5277
[29]Dai Y M,Akrap A,Schneeloch J,Zhong R D,Liu T S,Gu G D,Li Qand Homes C C 2014 Phys.Rev.B 90 121114
[30]Ling J W,Liu Y W,Jin Z,Huang S,Wang W Y,Zhang C,Yuan X,Liu S S,Zhang E Z,Huang C,Sankar R,Chou F C,Xia Z C and Xiu F X2018 Chin.Phys.B 27 017504