INO-CNR BEC Center

Transcription

1 INO-CNR BEC Center The INO-CNR team: CNR Researchers: PostDocs: Tom Bienaimé Giacomo Lamporesi, Gabriele Ferrari PhD students: Simone Serafini (INO), Eleonora Fava, Giacomo Colzi, Carmelo Mordini, Matteo Barbiero (Politecnico Torino/INRIM), Elena Iseni (INO)

2 experimental setup in Trento T=1.1 mk N= T=870 nk N=2 107 T=650 nk N= T=470 nk N=1,1 107 T=290 nk N=7 106 T<200 nk N=4 106 Many control knobs for realizing Hamiltonians in the lab! fermions and bosons interactions dispersion (also relativistic) temperature topology / dimensionality disorder gauge fields dynamics

3 Outline Main research lines: 1) Topological excitations in superfluids, characterization, dynamics, interactions 2) Quantum simulation of open problem in high-energy physics 3) Spinor Bose-Einstein condensates, polarizability, solitonic excitations 4) Optical atomic clocks Funding: Accordo di Programma with PAT QUIC - Quantum simulations of insulators and conductors FISH - Fundamental interaction simulations with quantum gases Research partner: INFN - TIFPA INRIM - Istituto Nazionale di Ricerca Metrologica (FET Proactive ) (INFN )

4 1- Quantum vortices in BECs Spontaneous and stochastic creation of vortices via the Kibble-Zurek mechanism Proposed in the context of cosmology and verified in condensed matter systems Second order phase transitions Finite rate crossing in trap slow quench fast quench free expansion Kibble, Physics Reports 67, 183 (1980) Zurek, Nature 317, 505 (1985)

5 1- Quantum vortices in BECs Spontaneous and stochastic creation of vortices via the Kibble-Zurek mechanism Proposed in the context of cosmology and verified in condensed matter systems Second order phase transitions Finite rate crossing Lamporesi et al., Nature Physics 9, 656 (2013) in trap slow quench fast quench free expansion Kibble, Physics Reports 67, 183 (1980) Zurek, Nature 317, 505 (1985)

6 1- Quantum vortices in BECs DENSITY OF DEFECTS: Critical exponents Geometry Dimensionality α N v τ Q a = 1.4 1D harmonic oscillator (Zurek, PRL 2009) a = 7/6 ~ 1.17 G.Lamporesi et al., Nat. Phys. 9, 656 (2013)

7 1- Characterization of the phase and density profile VORTEX ANTIVORTEX homodyne detection of the phase pattern by interfering two copies of the condensate S. Donadello et al., PRL 113, (2014)

8 1- Real-time dynamics of vortices Vortex dynamics and reconnections play a fundamental role in turbulent system In superfluid vortices are intrinsically simpler to study given the quantization constraints S. Serafini et al., arxiv:

9 2- Quantum simulation of open problem in high-energy physics Scientific motivation: The Standard Model has received impressive experimental proofs. However, fundamental problems are still open... The QCD phase diagram is still largely unknown! Exotic (color) fermionic superfluidity? Dynamics of deconfined quarks? How to solve these problems? Numerical approaches to quantum physics are extremely difficult for any classical hardware, even for supercomputers! (sign problem, dynamics...) Quantum simulator: dedicated quantum computer which can solve open dedicated quantum computer which can solve open problems problems of quantum physics by imitating the physics of quantum physics by imitating, with a well-controlled of the target system / model treatable system the physics of the target system / model

10 2- Quantum simulation of open problem in high-energy physics Scientific goal of the FISh experiment: engineer the interactions in ultracold quantum gases in order to realize quantum simulators for some aspects of high-energy physics, connected to the quark confinement in QCD Disclaimer: dedicated quantum computer which can solve open We don't (and cannot!) promise to perform a full quantum simulation of QCD problems of quantum physics by imitating the physics We plan to realize certain simplified models to make cold atoms behave as of the target system / model quark matter, to learn something new about basic phenomenology of QCD. Strategy: Coherent coupling between two internal states of a spinor BEC Generation of topological defects (domain walls on the relative phase, formally similar to the kink in the sine-gordon field theory)

11 2- Quantum simulation of open problem in high-energy physics Analogy vortex/antivortex molecule qq bound state in a meson In 2D vortices exist only as vortex-antivortex bound state Binding force loosely dependent on the relative distance (domain wall surface tension) The binding force of the vortex/antivortex molecule (bound by the domain wall) would simulate the attraction between quark and antiquark K. Kasamatsu et al. PRL 93, (2004) Characterize the excitations VS: gas density and interactions, coupling, external potentials temperature.

12 4- Optical atomic clocks Applied sciences: GPS navigation Space navigation telecommunications financial transactions cryptography geodesy... Fundamental sciences: Text of theories at the ultimate level Check of constancy of physical constants VLBI...

13 4- Optical atomic clocks The activities in Trento along this line aim at developing a source of cold Strontium atoms at conditions of temperature and confinement suitable to the accurate interrogation of the optical clock transition. Once operational and tested, the atomic source will be transferred to INRIM in Torino for operation and characterization in the final optical clock setup. We are currently working on the design and assembly of the cold atomic source, as well as the assembly of the computer controlled electronics required for the preparation and interrogation of the atomic sample.

14 3- Spinor Bose-Einstein condensates D. M. Stamper-Kurn et al. PRL 88, 2027 (1998) Homogeneous systems: miscibility VS immiscibility J. Stenger et al. Nature 396, 345 (1998) Buoyancy VS magnetic polarizability

15 3- Spinor Bose-Einstein condensates Magnetic polarizability T. Bienaimé et al., PRA 94, (2016)

16 3- Spin-dipole oscillation in BEC polarized sample spin mixsture NOTE: the spin-dipole oscillation is the analog of the giant dipole resonance of nuclear physics, where neutrons and protons oscillate with opposite phase T. Bienaimé et al., PRA 94, (2016)