1Department of Physics, Tohoku University, Sendai, Miyagi 980-8578, Japan
2Department of Physics, Chittagong University of Engineering & Technology, Chittagong-4349, Bangladesh
3ERATO Nuclear Spin Electronics Project, Sendai, Miyagi 980-8578, Japan
4State Key Laboratory of Superhard Materials and Institute of Atomic and Molecular Physics,
Jilin University, Changchun 130012, People’s Republic of China
5Homer L. Dodge Department of Physics and Astronomy, University of Oklahoma, 440 West Brooks, Norman, Oklahoma 73019-2061, USA
6WPI Research Center, Advanced Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
*E-mail: mohi_cuet@yahoo.com
Narrow band-gap semiconductor InSb has long been considered as potentially exciting materials for next-generation high-speed electronics, quantum devices and spintronics applications due to its high room-temperature mobility (77000 cm2/Vs), significant ballistic transport length, large Lande g factor, high nuclear spin (In=9/2, 121Sb I = 5/2, 123Sb I = 7/2) and high spin-orbit coupling. Nuclear spins in low-dimensional semiconductor structures have attracted growing interest because the long spin coherence time of nuclei facilitates the implementation of quantum information processing (QIP). The quadrupole splitting of 115In have been reported in a single InSb two dimensional electron gas (2DEG) that are of practical importance for the coherent control of the ten nuclear-spin quantum levels and for the implementation of multiple NMR-based quantum bits (≥2) [1, 2]. The success of gate controlled InSb quantum wells [3, 4] allows us to perform pump and probe technique to investigate temperature dependent nuclear spin relaxation time T1 at different filling factors (ν ). Collective spin excitations in the domain walls enhance dynamic nuclear polarization in the quantum Hall ferromagnet around 2 characterized by a short (~ 60 sec) and temperature-independent T1. On the other hand, relatively long (~ 400 sec) and temperature dependent T1with following Korringa law have been demonstrated in the absence of the domains as well as collective spin texture at around 3. In addition, the large Zeeman, cyclotron and exchange energy scales of the InSb 2DEG favour to demonstrate the resistively detected NMR (RDNMR) signal at elevated temperature up to 6 K. Our results clearly show that the InSb 2DEG is a suitable candidate for implementation of the high temperature nuclear-spin based QIP.
Ref:
[1] H. W. Liu et al. Phys. Rev. B 82, 241304(R) (2010).
[2] K. F. Yang et al., Appl. Phys. Lett. 98, 142109 (2011).
[3] M. M. Uddin et al., Appl. Phys. Lett. 101, 233503 (2012).
[4] M. M. Uddin et al., Appl. Phys. Lett. 103, 123502 (2013).
Fig. : Filling factors (ν) dependence of nuclear spin relaxation time T1 at different temperature. Top axis shows the filling factors are calculated by gate bias (Vg) in bottom axis.