Transcript Magnetoresistance InAs1-xNx 200K 80K 40K T = 2K 10K T=2K xx/xx (%) x=0.2% x=0% 0.5 80K 40K 10K T=2K 0.0 0.1 B (T) x=0.4% 0.2 x=0.6% x=1.0% 0 T=2K The LMR is a classical effect associated with macroscopic nonhomogeneities.

Magnetoresistance
2
InAs1-xNx
200K
80K
40K
T = 2K
10K
T=2K
xx/xx (%)
0
600
x=0.2%
x=0%
0.5
80K
40K
10K
T=2K
300
0.0
0.1
B (T)
x=0.4%
0.2
x=0.6%
x=1.0%
0
0
T=2K
2
4
The LMR is a classical effect
associated with macroscopic nonhomogeneities. Its strength scales
with the electron mobility.
•
x=1.0%
-0.5
6
8
B (T)
10
12
Patanè et al. PRB 80 115207 ’09
14
Linear-MR
Xu et al., Nature 390, 57 ’97
x=0.2%
200K
0.0
•
Negative-MR
Ashuler et al., PRB 22, 5142 ’80
The NMR is a quantum effect due
to
weak-localization.
The
minimum of the MR occurs when
the magnetic length (e/hB)1/2
becomes equal to 2lj, where lj ~
100nm is the electron coherence
length.
Comparing III-N-Vs
InAsN
Energy
Eg-G = 0.35 eV
EL=1.08 eV
EX=1.37 eV
X-valley
G-valley
GaAsN
Energy
X-valley
N
<100>
G-valley
L-valley
Eg-G = 1.42 eV
EL~0.3 eV
EX~0.3 eV
L-valley
N
<111>
<100>
<111>
Wave vector
The energy of the N-level (EN~ 1eV)
is larger than the threshold energy
for impact ionization (~ Eg-G).
The energy of the N-level (EN~ 0.2eV)
is smaller than the threshold energy for
impact ionization (~ Eg-G).
GaAsN: RELIEF-effect
Resonant Electron Localization In Electric Field
GaAs
e
4.2K
4
80K
10K
20K
X
N
70K
30K
40
L
k
0
0.0
I (mA)
Γ
2
0.4
65K
0.8
60K
20
55K
Balance between the resonant
localization of electrons at N-levels
and scattering phenomena leads to
Negative Differential Resistance.
See also theory-work of J. Rorison and
N. Vogiatzis (Un. Bristol, UK)
0
0.0
50K
45K
40K
30K
0.4
0.8
V (V)
1.2
1.6
PRL 91, 126802 ’03
APL 88 032107 ’06
JPCM 21, 174209 ’09