Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 Electronic properties of HTS and novel superconductors Intrinsic Josephson Tunnelling between atomic layers in HTS Fundamental physics + “blue sky” applications (THz spectroscopy, single-electron and quantum devices) microwave properties Fundamental physics + immediate applications Close synergy with “Emerging Device Technologies” –EE CMP includes - “Emerging Device Physics” introduction

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 Intrinsic Josephson Tunnelling between atomic layers in HTS Birmingham early SQUID measurements confirmed electron-pairing in d-wave HTS also first HTS quantum devices and microwave applications Cooper pairs excitations volts current volts 2  - energy gap Ij sin  Intrinsic tunnelling

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 Intrinsic Josephson Junction Tunnelling in BSCCO BSCCO-2212 Bi 2 Sr 2 CaCu 2 O 8 electrical anisotropy ~10 5 quasi-2d HTc superconductor d-wave l =2 Cooper pairs Energy gap  (T,B)  (  )~ cos2   line nodes - gap 0 inter-layer quantum tunnnelling BSCCO xtal

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 BSSCO cleaves atomically flat ~ mm Ion beam and chemical photolithography 10 – 50  m mesa structures 4-point VI measurements across 1-50 atomic layers atomically defined intrinsic JJs Mesa structures

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 Birmingham measurements Intrinsic tunnelling across individual atomic layers 10 Josephson junctions in series d-wave Cooper pair and quasi-particle tunnelling 4-point IV measurements 20 ns resolution tunnelling dynamics. Measurement expertise x x x x x

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 Future - quantum physics of atomically-defined structures Intrinsic single-electron array devices Intrinsic Coulomb-blockade array structures Quantum coherence/computing – Q-bits Also THz spectroscopy (ac Josephson) ~ 100 nm HTS mesa (FIB -Nature + Nano-technology in Engineering) 1 nm Quantum devices Charging energy e 2 /2C >> kT Resistance/junction > R quantum = h/e 2

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 Spintronics on individual atomic layers with Chris Muirhead and Mark Colclough Spintronics(2) V Measure changes in T c and Josephson current on the top atomic plane

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 Birmingham facility is unique Very high resolution/sensitivity MHz - 40 GHz 50 mK to room temperature B up to 16T Low T - T c often ~ 1K High B - Hc 2 often ~ 10T Microwave physics -HTS and other novel s/c existing 5-year portfolio programme CEG, Dr Rod Ormeno and Tim Barraclough Microwaves

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 What do microwaves tell us? Complex conductivity  =  1 + i  2 “normal” electrons s/c electrons Penetration and losses B(r) ~ exp(-x/   wave penetration and losses

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 Novel dielectric resonator and typical data Sr 2 RuO 4 p-wave s/c Cavity measurements Position and width to 50Hz in 10GHz 0 1K Measure resonant frequency shifts and Q-values - sub 1mm single crystals

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 novel materials -novel pairing- novel physics heavy fermions UPt 3, CeCoIn 5 pairing ? Strontium Ruthenate p-wave HTc d-wave pairing Organic s/c  -(ET) 2 Cu(SCN) 2 pairing ? MgB 2 Tc~38K s-wave, but 2 energy gaps Also conventional s/c T meas < 1K h  > kT B measurements Novel materials

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004 EE - Emerging Device Technologies Group Prof Mike Lancaster, Dr Tim Jackson, Dr Anton Velichko + 4 others Close synergy in research non-linear properties, spin-injection tuning of filters, ferrites, ferro-electrics,dielectrics continued collaboration involving frontier physics EPSRC views collaboration as a major Birmingham strength Birmingham Microwave programme Physics - fundamental science Electrical Engineering – applications filters for mobile communications front-end filters for radio astronomy - Jodrell Bank Telescope delay lines and signal processing tuneable filters with ferroelectrics Synergy with EE

Condensed Matter Physics CEG - Science and microwaves26th Jan 2004