Magnetotransport with in-situ sample rotation.
| FEATURES | DRESDEN | TOULOUSE | NIJMEGEN | GRENOBLE |
|---|---|---|---|---|
| Local Contact | Toni Helm |
Walter Escoffier Michel Goiran Mathieu Pierre |
Steffen WIEDMANN, Uli ZEITLER |
Benjamin Piot |
| Field range | 0 ... 90 T | 0 - 70 T | 0 ... 38 T | 0 - 36 T |
| Temperature range | 300 K down to 1.3 K. Lower temperatures down to ~0.6 K are possible using a ³He system with a 24mm bore coil (62 & 70 T) | Standard: 1.6 - 350 K On option: 350mK - 350K | 0.3 ... 30 K (3He system) 1.4 … 380 K (flow cryostat) 0.05 ... 4 K (dilution refrigerator, on request) | 25 mK – 300 K |
| Sample size | The maximum sample space available is 10 x 6 x 2 mm. Angular-dependent measurements and measurements in 95 T coils can be performed on two samples simultaneously, however restricting their size to 4 x 3 mm. | Typical samples: nano-devices or 2DEGs on chip Chip size: maximum 3.5 x 3.5 mm² | i) sample in LCC-20 chip carrier < 5x5 mm2 (inside LCC-20 dye); ii) sample directly mounted on platform < 10x10 mm2; < 1 mm thickness (typical) sample resistance: μΩ … MΩ (AC using lock-in amplifiers) < 1 GΩ (DC, typically, using nanovoltmeters) | mK Range: 5×5 mm sample with in-situ rotation (custom mount). Pluggable 8 Pin DIL chip carrier without rotation. T =1.2 K – 300 K: Pluggable 8 or 16 Pin DIL/DIP chip carriers (B=30T) or custom mount (for B=36T and in-situ rotation). |
| Sensitivity | Relative resolutions of 10-4 are achieved. | variable | ||
| Measurement range | resistance ranging from Ohms to MOhms Ohmic contacts are preferred | |||
| Typical experiment | Typical AC-excitation currents range from 1 μA to 100 mA with frequencies between 2 and 200 kHz. | Magneto-resistance and Hall effect - Current or voltage biasing - DC or AC (lock-in at 10kHz minimum frequency) measurement - Gate voltage control (top and/or back gate) - Safe handling of electrostatic-sensitive devices - Sample tilting with respect to B (perpendicular to parallel field) - UV and visible light illumination | R(B,T,ϑ,Vg,...)
sweep rates (typical) 0.5 … 5 T/min
Bias current: < 1 nA …10 mA (typical, depending on sample impedance)
Gate voltage: ±100 V (typical)
|
Transport measurements, capacitance measurements, detection of Radio frequencies (ED - NMR), microwaves, far and near infrared-induced resonances. |
| Sample Holder | The standard sample holder can accommodate up to three samples when both longitudinal resistivity and Hall effect are measured. | 
The chip is glued on a ceramic holder which is mounted on a commercial 10 or 8-pin connector. The contact pads are connected to those on the ceramic either with wedge bonding or manually with silver-pasted gold wire. |
a) rotate field from parallel to perpendicular orientation b) rotate field inside sample plane (azimuthal rotation) c) fixed angle (ϑ=0°), sample perpendicular to field | variable, many configurations compatible with standard 8 or 16 Pin DIL/DIP chip carrier. |
| Sample environment | Gaseous helium from 300K down to 4K, liquid helium or ³He below | Helium or vacuum (only for experiments up to 60T in large-bore coils) | liquid helium or gas helium. | |
| Examples | Measurement examples: Magnetic quantum oscillations in the electron-doped high-Tc superconductor Nd2−xCexCuO4 [1] 
Extremely large magnetoresistance and ultrahigh mobility in the topological Weyl semimetal candidate NbP [2] 
Linear magnetoresistance in mosaic-like bilayer graphene [3] 
[1] T. Helm et al., Physical Review B 92, 094501 (2015)
[2] C. Shekhar et al., Nature Physics 11, 645–649 (2015)
[3] F. Kisslinger et al., Nature Physics 11, 650–653 (2015) |
Exfoliated graphene - Phys. Rev. Letters 107, 126806 (2011) SiC graphene-Phys. Rev. Letters 117, 237702 (2016) Graphene nanoribbons - Phys. Rev. Letters 107, 086601 (2011) Semiconducting nanowires - Phys. Rev. Letters 112, 076801 (2014) Topological insulators - Nano Letters 15, 7503–7507 (2015) 2DEG at complex oxide interfaces - Appl. Phys. Letters 109, 122106 (2016) Bottom-up conducting nano-objects - Nanoscale 9, 14635 (2017) | Ising superconductivity: PNAS 115, 3551 (2018);Science 350, 1353 (2015); Fractal states in graphene: PNAS 115, 5135 (2018);Quantum Oscillations in ZrSiS: Nature Physics 14 (2018), 178-183; FQHE and Wigner solid in ZnO: Nature Communications 9 (2018), 4356 ; QHE in InSe: Nat. Nanotechnol. 12, 223 (2017) | Transport with in-situ rotation, capacitance measurements at mK temperatures, mK transport with optical or microwave excitation, resistively detected NMR and ESR, etc… |