Part3:Superfluidity: k Flow via obstacles, Persistent Currents & Quantised Vortices. Marzena Szymanska

Transcription

1 Part3:Superfluidity: k Flow via obstacles, Persistent Currents & Quantised Vortices Marzena Szymanska

2 Collaborators Theory F. M. Marchetti E. Cancellieri C. Tejedor D. Whittaker Experiment D. Sanvitto, G. Tosi, L. Viña, D. Krizhanovskii, M. Skolnick L. Marrucci, A. Lemaître, J. Bloch

3 Superfluidity in equilibrium systems persistent [Steinhauer et al. PRL (2002)]

4 Superfluidity in equilibrium systems persistent Frictionless via macroscopic defect in the fluid no drag force drag force [Onofrio et al., PRL (2000)]

5 Superfluidity in equilibrium systems persistent [Abo-Shaeer et al. Science (2001)] ground state is less & need external driving

6 Superfluidity in equilibrium systems persistent Gauss-Laguerre beam rotating drive [Ryu et al. PRL (2007)]

7 Superfluidity in equilibrium systems persistent Gauss-Laguerre beam rotating drive [Ryu et al. PRL (2007)]

8 Superfluidity out of equilibrium (incoherent pump) persistent polariton lifetime

9 E [mev] Superfluidity out of equilibrium (incoherent pump) persistent [Wouters & Carusotto, PRL (2007)] [Szymanska et al., PRL (2006)] Excitations Luminescence spectrum emission angle [degree]

10 Superfluidity out of equilibrium (incoherent pump) Frictionless persistent drag force drag v>v c little drag v<v c [Wouters & Carussotto, arxiv (2010)]

11 Superfluidity out of equilibrium (incoherent pump) persistent Ground state with a vortex pined by disorder vortex m=1 phase 2 0 interference [Lagoudakis et al. Nature Phys (2008)]

12 Superfluidity out of equilibrium (incoherent pump) pump persistent no-sf trap [Lagoudakis et al. Science (2009)] decay [Keeling & Berloff PRL (2008)]

13 Superfluidity out of equilibrium (incoherent pump) persistent no-sf (parametrical pump) signal

14 Optical parametric oscillator (OPO) Stimulated scattering from pump to signal and idler Pump threshold U(1) symmetry (phase rotation) U(1) spontaneous symmetry breaking: gapless and diffusive Goldstone mode [Wouters & Carusotto PRA (2007)]

15 Optical parametric oscillator (OPO) (incoherent pump) persistent no-sf (parametrical pump)

16 Optical parametric oscillator (OPO) (incoherent pump) persistent no-sf (parametrical pump) Above OPO threshold Frictionless (no scattering in momentum) [Amo et al. Nature (2009)]

17 Theoretical Model Gross-Pitaevskii equation with pump & decay coupling interaction decay cw pump (OPO) C (,k)

18 Persistent after a rotating drive pulse pulsed probe Gauss-Laguerre pulse - stirring the polariton superfluid for a short (2ps) time

19 Metastable persistent Vortex imprinting into signal (&idler) for strong enough probe pulsed probe [Sanvitto, Marchetti, Szymanska et al., Nature Phys. (2010) (arxiv/ )] [Marchetti, Szymanska et al. PRL (2010), arxiv/ ]

20 Metastable persistent [Sanvitto, Marchetti, Szymanska et al., Nature Phys. (arxiv/ ) 2010]

21 Metastable persistent [Sanvitto, Marchetti, Szymanska et al., Nature Phys. (arxiv/ )]

22 Optical parametric oscillator (OPO) (incoherent pump) persistent no-sf (parametrical pump)

23 Vortex healing length Independent on probe size, but on OPO properties only [Marchetti, Szymanska et al., arxiv/

24 Vortex healing length Independent on probe size, but on OPO properties only Only signal & idler carry a vortex [Marchetti, Szymanska et al., PRL (2010) arxiv/ ] signal m=-1 idler m=+1 pump m=0 [Krizhanovskii et al. PRL (2010)] 10 m

25 Vortex healing length Independent on probe size, but on OPO properties only Only signal & idler carry a vortex [Marchetti, Szymanska et al., PRL (2010) arxiv/ ] [Krizhanovskii et al. PRL (2010)] Signal int. [a.u.] checked by weak continuouswave imprinting beam

26 Optical parametric oscillator (OPO) (incoherent pump) persistent no-sf (parametrical pump) (coherent pump) Below OPO threshold No spontaneous symmetry breaking but satisfied [Ciuti & Carusotto PRA (2007)]

27 Optical parametric oscillator (OPO) (incoherent pump) (parametrical pump) Frictionless below critical velocity Phase fixed by the pump thus no persistent no-sf (coherent pump) Below OPO threshold [Amo et al. Nature Phys (2009)]

28 Frictionless of the OPO Gross-Pitaevskii equation with pump & decay

29 Frictionless of the OPO Gross-Pitaevskii equation with pump & decay Drag force:

30 Conclusions a novel light-matter superfluid out of equilibrium 1. Frictionless : almost vanishing drag force (incoherent pump) (parametrical pump) persistent no-sf (coherent pump) 10 m

31 Conclusions a novel light-matter superfluid out of equilibrium 1. Frictionless : almost vanishing drag force 2. Persistent currents in the OPO regime 3. Vortex healing length 10 m (incoherent pump) (parametrical pump) persistent no-sf (coherent pump)

32 Conclusions a novel light-matter superfluid out of equilibrium 1. Frictionless : almost vanishing drag force 2. Persistent currents in the OPO regime 3. Vortex healing length. Stable & unstable doubly 10 m (incoherent pump) (parametrical pump) persistent no-sf (coherent pump)

33 Conclusions a novel light-matter superfluid out of equilibrium So far experiments and numerical simulations Analytical theory of non-equilibrium superfluidity still missing! 10 m (incoherent pump) (parametrical pump) persistent no-sf (coherent pump)