Spin States of Holes in Ge/Si Nanowire Quantum Dots

被引：75

作者：

Roddaro, S. ^{[1
]}

Fuhrer, A. ^{[1
]}

Brusheim, P. ^{[1
]}

Fasth, C. ^{[1
]}

Xu, H. Q. ^{[1
]}

Samuelson, L. ^{[1
]}

Xiang, J. ^{[2
]}

Lieber, C. M. ^{[2
]}

机构：

[1] Lund Univ, Solid State Phys Nanometer Struct Consortium, S-22100 Lund, Sweden

[2] Harvard Univ, Dept Chem & Chem Biol, Cambridge, MA 02138 USA

来源：

PHYSICAL REVIEW LETTERS | 2008年 / 101卷 / 18期

关键词：

D O I：

10.1103/PhysRevLett.101.186802

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

We investigate tunable hole quantum dots defined by surface gating Ge/Si core-shell nanowire heterostructures. In single level Coulomb-blockade transport measurements at low temperatures spin doublets are found, which become sequentially filled by holes. Magnetotransport measurements allow us to extract a g factor g(*)approximate to 2 close to the value of a free spin-1/2 particle in the case of the smallest dot. In less confined quantum dots smaller g factor values are observed. This indicates a lifting of the expected strong spin-orbit interaction effects in the valence band for holes confined in small enough quantum dots. By comparing the excitation spectrum with the addition spectrum we tentatively identify a hole exchange interaction strength chi approximate to 130 mu eV.

引用

页数：4

共 20 条

[1] Tunable effective g factor in InAs nanowire quantum dots -: art. no. 201307 [J].

Björk, MT ;

Fuhrer, A ;

Hansen, AE ;

Larsson, MW ;

Fröberg, LE ;

Samuelson, L .

PHYSICAL REVIEW B, 2005, 72 (20)

[2] EFFECTIVE MASSES OF HOLES AT GAAS-ALGAAS HETEROJUNCTIONS [J].

BROIDO, DA ;

SHAM, LJ .

PHYSICAL REVIEW B, 1985, 31 (02) :888-892

[3] Vertical wrap-gated nanowire transistors [J].

Bryllert, T ;

Wernersson, LE ;

Löwgren, T ;

Samuelson, L .

NANOTECHNOLOGY, 2006, 17 (11) :S227-S230

[4] Large variations in the hole spin splitting of quantum-wire subband edges [J].

Csontos, Dan ;

Zulicke, Ulrich .

PHYSICAL REVIEW B, 2007, 76 (07)

[5] Zeeman splitting in ballistic hole quantum wires [J].

Danneau, R. ;

Klochan, O. ;

Clarke, W. R. ;

Ho, L. H. ;

Micolich, A. P. ;

Simmons, M. Y. ;

Hamilton, A. R. ;

Pepper, M. ;

Ritchie, D. A. ;

Zulicke, U. .

PHYSICAL REVIEW LETTERS, 2006, 97 (02)

[6]

*EPAPS, EPRLTAO101042844 EPA, P402

[7] Tunable double quantum dots in InAs nanowires defined by local gate electrodes [J].

Fasth, C ;

Fuhrer, A ;

Björk, MT ;

Samuelson, L .

NANO LETTERS, 2005, 5 (07) :1487-1490

[8] Singlet-triplet transition tuned by asymmetric gate voltages in a quantum ring [J].

Fuhrer, A ;

Ihn, T ;

Ensslin, K ;

Wegscheider, W ;

Bichler, M .

PHYSICAL REVIEW LETTERS, 2003, 91 (20)

[9] Few electron double quantum dots in InAs/InP nanowire heterostructures [J].

Fuhrer, Andreas ;

Froberg, Linus E. ;

Pedersen, Jonas Nyvold ;

Larsson, Magnus W. ;

Wacker, Andreas ;

Pistol, Mats-Erik ;

Samuelson, Lars .

NANO LETTERS, 2007, 7 (02) :243-246

[10] Giant anisotropy of Zeeman splitting of quantum confined acceptors in Si/Ge [J].

Haendel, KM ;

Winkler, R ;

Denker, U ;

Schmidt, OG ;

Haug, RJ .

PHYSICAL REVIEW LETTERS, 2006, 96 (08) :1-4

← 1 2 →