Laboratorio de Bajas Temperaturas

Universidad Autónoma de Madrid

http://lbtuam.es

Very high magnetic field Scanning

Tunneling Microscopy

One of the 29 “Landmarks”

Members:

• CNRS (France)

• HZDR (Germany)

• RU/FOM (Holland)

• EPSRC (UK)

New research line

Very high magnetic field Scanning Tunneling Microscopy

New research line

Very high magnetic field Scanning Tunneling Microscopy

Current falicities at LBTUAM

• Dil fridge STM (15 mK)+ 5T-1T-1T (2102)

• Dil fridge STM (30 mK)+ 9T (2102)

• Dil fridge STM (7 mK)+ 9T(9102)

• 4K-cryostat + 17 T (3)

Under construction

• Dil fridge STM (7mK) + 17T (1.6103)

Near future facilities

• Dil fridge STM (7 mK) + 22T (2.2103)

• Hibrid magnet STM (>30 T) (102)Y.J. Song, et al., Review of Scientific Instruments 81, 121101 (2010).

New research line

Very high magnetic field Scanning Tunneling Microscopy

Current falicities at LBTUAM

• Dil fridge STM (15 mK)+ 5T-1T-1T (2102)

• Dil fridge STM (30 mK)+ 9T (2102)

• Dil fridge STM (7 mK)+ 9T(9102)

• 4K-cryostat + 17 T (3)

Under construction

• Dil fridge STM (7mK) + 17T (1.6103)

Near future facilities

• Dil fridge STM (7 mK) + 22T (2.2103)

• Hibrid magnet STM (>30 T) (102)Y.J. Song, et al., Review of Scientific Instruments 81, 121101 (2010).

Dilution refrigerator STM (7 mK + 17 T)

KelvinoxMX + versatil insert EX400 Low consumption 100 L dewar + 17T SC magnet

New high magnetic field STM

Compact very low temperature STM with mechanically

driven horizontal linear positioning state

H. Suderow, I. Guillamón and S. Vieira

Rev Sci Inst, 033771, 82 (2011)

100 mK

<15 meV

1. Spectroscopy

-1,0 -0,5 0,0 0,5 1,00,0

0,5

1,0

1,5

2,0

Experiment

Fit:

= 0.2 meV

T = 0.1 K

Norm

aliz

ed C

on

du

ctan

ce

Voltage (mV)

Al-Au

Spectroscopy in low Tc Superconductors

Rev Sci Inst, 033771, 82 (2011)

2. Mechanical pulling mechanism to move the tip over the sample

Macroscopic movement

2 mm

Nanoscopic movement

FIB milled paths in AuChange the scanning window in a controlled way at nanoscale and

low temperatures

We can put several sampleswhich are accesible in a

controlled way

Rev Sci Inst, 033771, 82 (2011)

2. Mechanical pulling mechanism to move the tip over the sample

Macroscopic movement

2 mm

Nanoscopic movement

FIB milled paths in AuChange the scanning window in a controlled way at nanoscale and

low temperatures

We can put several sampleswhich are accesible in a

controlled way

Rev Sci Inst, 033771, 82 (2011)

3. Sample preparation method at low temperatures (in-situ)

Visualizing electronic correlations under high magnetic fields

Landau level spectroscopy

exp (-k/ l B)

• Band structure at varying energy: empty

and occupied states

• Local measurements: at cleanest areas

• Spatial dependence: Inside vortex cores

𝐸𝑛 = 𝑛 +1

2ℏ𝜔𝑐 𝑛 = 0,1,2, … .