Independent Regulation Of Rashba And Dresselhaus Spin-orbit Coupling Parameters In InSb Quantum Wells

InSb is a narrow-gap material which has a largest g-factor,highest room temperature mobility,and a largest spin-orbit interaction?SOI?compare to the other III-V compound semiconductors.Therefore,InSb and InSb quantum wells have drawn attention in several fields,ranging from the quest for new electronic devices^[1][2]to magnetoresistive devices^[3][4]and spin-based electronics^[5].The spin orbit effect of a semiconductor heterostructures comes from two different inversion asymmetries,the structure inversion asymmetry and the bulk inversion asymmetry.The bulk inversion asymmetry is due to the lack of inversion center in the zinc-blende structure made of two different elements which leads to a Dresselhaus spin splitting consisting of both linear and cubic in-plane wave vector terms.The structure inversion asymmetry is due to the asymmetry of the quantum well,which causes the Rashba spin splitting term which is linear in wave vector.By adjusting the ratio of Rashba and Dresselhaus SOI parameters the spin relaxation can be suppressed and resulting a long spin lifetime.Therefore,the regulation of the two parameters is very important for the development of spin-based devices as well as the study of spintronics.Hitherto,the regulation of Spin-orbit interaction?SOI?has been realized in several low-dimensional heterostructures.A gate voltage is proved to be very effective to control the Rashba SOI parameters via the change of structure inversion symmetry in a quantum well.However,the Dresselhaus SOI was usually ignored.Hydrostatic pressure is another technique to control SOI via the direct variation of the band gap.However,previous study on a symmetric GaAs quantum well?the Rashba SOI is negligible?conclude that the effect of pressure on the Dresselhaus SOI is not important compared to the role of electron density,this is also reasonable considering the relatively wide band gap and its small pressure coefficient of GaAs.Here,we systematically study the pressure effect on InSb quantum well with a top gate,the key idea is that we combine both the pressure and gate voltage to achieve independent regulation of Rashba and Dresselhaus SOI parameters in InSb quantum wells.The SOI strength can be estimated from the beating pattern of the Shubnikov–de Haas?SdH?oscillations,but this is not the case for InSb,because the large Lande g-factor of InSb resulting a strong Zeeman splitting which is comparable to the spin-orbit splitting in a finite magnetic field,therefor we employ the low-field weak antilocalization?WAL?technique to determine the SOI strength.The Rashba and Dresselhaus SOI parameters in InSb quantum wells under different pressure and gate voltage conditions are extracted by fitting the attained WAL data with Iordanskii,Lyanda-Geller,Pikus?ILP?model.Our results clearly demonstrate that both the pressure and gate voltage are very effective to control the SOI strength in InSb quantum wells.Especially,by combining both the pressure and gate voltage the independent control of Rashba and Dresselhaus SOI parameters is realized for the first time,which is an important step for the development of InSb-based spintronic devices and the study of spin-related phenomena.