Aharonov-Casher EffectAharonov-Casher Effect

Experimental MethodExperimental Method

Making the SpecimenMaking the Specimen

Yttrium Barium Copper OxideYttrium Barium Copper Oxide

(YBa(YBa22CuCu33OO7-7-))

Making the SpecimenMaking the Specimen

Crushing old YBCO Crushing old YBCO specimensspecimens

Making the SpecimenMaking the Specimen

Crushing old YBCO Crushing old YBCO specimensspecimens

Filling die with Filling die with YBCO powderYBCO powder

Add ethanolAdd ethanol Compress in viceCompress in vice

Making the SpecimenMaking the Specimen

Crushing old YBCO Crushing old YBCO specimensspecimens

Filling die with Filling die with YBCO powderYBCO powder

Add ethanolAdd ethanol Compress in viceCompress in vice SinterSinter

Making the SpecimenMaking the Specimen

Crushing old YBCO Crushing old YBCO specimensspecimens

Filling die with Filling die with YBCO powderYBCO powder

Add ethanolAdd ethanol Compress in viceCompress in vice SinterSinter Cut & Polish Cut & Polish

SpecimenSpecimen

Finished SpecimenFinished Specimen

ExperimentsExperiments

Testing SuperconductivityTesting Superconductivity

(AC Resistivity)(AC Resistivity)

Experimental SetupExperimental Setup

Helium Fridge Specimen “Cold Finger”

Experimental SetupExperimental Setup

SelectableResistor

(1kΩ)

Cathode RayOscilloscope

Ammeter

Lock-in Amplifier

FunctionGenerator

VoltageSource

Computer

Testing Circuit DiagramTesting Circuit Diagram

SpecimenSpecimen

Lock-In AmpLock-In Amp

ACAC VoltageVoltage

VoltageVoltageSenseSenseMeterMeter CurrentCurrent

SenseSenseMeterMeter

ThermocoupleThermocouple

ResultsResults

ExperimentsExperiments

Aharonov-Casher EffectAharonov-Casher Effect

Experimental SetupExperimental Setup

Experimental SetupExperimental Setup

SelectableResistor

(1kΩ)

Cathode RayOscilloscope

Ammeter

VoltageSource

Computer

RampGenerator

Circuit DiagramCircuit DiagramVoltage RampVoltage Ramp

& 1000& 1000µF CapacitorµF Capacitor

DC VoltageDC Voltage& Resistor& Resistor

LeCroy OscilloscopeLeCroy Oscilloscope

““Cold Finger”Cold Finger”

Measuring The EffectMeasuring The Effect

Charge “ramp” in Charge “ramp” in centrecentre

Causes frequency Causes frequency in V/Ain V/A

Analysed by Fast Analysed by Fast Fourier Transform Fourier Transform (FFT)(FFT)

Measuring The EffectMeasuring The Effect

LeCroy Dual-OscilloscopeLeCroy Dual-Oscilloscope

Real-time FFT

Difference betweenSaved & average

Averaged FFT

Saved FFT

Possible SolutionsPossible Solutions

Noise-free environmentNoise-free environment More accurate voltage rampMore accurate voltage ramp Use thin film sampleUse thin film sample Better capacitance calculationBetter capacitance calculation