Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Giant g factor tuning of long-lived electron spins in Ge   Control of electron spin coherence via external fields is fundamental in
spintronics. Its implementation demands a host material that accommodates the
highly desirable but contrasting requirements of spin robustness to relaxation
mechanisms and sizeable coupling between spin and orbital motion of charge
carriers. Here we focus on Ge, which, by matching those criteria, is rapidly
emerging as a prominent candidate for shuttling spin quantum bits in the mature
framework of Si electronics. So far, however, the intrinsic spin-dependent
phenomena of free electrons in conventional Ge/Si heterojunctions have proved
to be elusive because of epitaxy constraints and an unfavourable band
alignment. We overcome such fundamental limitations by investigating a two
dimensional electron gas (2DEG) confined in quantum wells of pure Ge grown on
SiGe-buffered Si substrates. These epitaxial systems demonstrate exceptionally
long spin relaxation and coherence times, eventually unveiling the potential of
Ge in bridging the gap between spintronic concepts and semiconductor device
physics. In particular, by tuning spin-orbit interaction via quantum
confinement we demonstrate that the electron Land\'e g factor and its
anisotropy can be engineered in our scalable and CMOS-compatible architectures
over a range previously inaccessible for Si spintronics.

22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
9
The categories of this paper are: nlin
21
The categories of this paper are: adap-org
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
0
The categories of this paper are: hep-ph
14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics