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Schäfer F, Herrera I, Cherukattil S, Lovecchio C, Cataliotti FS, Caruso F, Smerzi A. Experimental realization of quantum zeno dynamics. Nat Commun 2015; 5:3194. [PMID: 24476716 PMCID: PMC3916840 DOI: 10.1038/ncomms4194] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2013] [Accepted: 01/02/2014] [Indexed: 11/09/2022] Open
Abstract
It is generally impossible to probe a quantum system without disturbing it. However, it is possible to exploit the back action of quantum measurements and strong couplings to tailor and protect the coherent evolution of a quantum system. This is a profound and counterintuitive phenomenon known as quantum Zeno dynamics. Here we demonstrate quantum Zeno dynamics with a rubidium Bose–Einstein condensate in a five-level Hilbert space. We harness measurements and strong couplings to dynamically disconnect different groups of quantum states and constrain the atoms to coherently evolve inside a two-level subregion. In parallel to the foundational importance due to the realization of a dynamical superselection rule and the theory of quantum measurements, this is an important step forward in protecting and controlling quantum dynamics and, broadly speaking, quantum information processing. While a quantum system is always disturbed by any observation, one can exploit the back action of measurements and strong couplings to tailor the system evolution via quantum Zeno dynamics. Schäfer et al. demonstrate quantum Zeno dynamics in a five-level Hilbert space using a 87Rb Bose–Einstein condensate.
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Affiliation(s)
- F Schäfer
- 1] LENS-Università di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy [2] Dipartimento di Fisica ed Astronomia, Via Sansone 1, 50019 Sesto Fiorentino, Italy
| | - I Herrera
- LENS-Università di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
| | - S Cherukattil
- LENS-Università di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
| | - C Lovecchio
- LENS-Università di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy
| | - F S Cataliotti
- 1] LENS-Università di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy [2] Dipartimento di Fisica ed Astronomia, Via Sansone 1, 50019 Sesto Fiorentino, Italy [3] QSTAR, Largo Enrico Fermi 2, 50125 Firenze, Italy
| | - F Caruso
- 1] LENS-Università di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy [2] Dipartimento di Fisica ed Astronomia, Via Sansone 1, 50019 Sesto Fiorentino, Italy [3] QSTAR, Largo Enrico Fermi 2, 50125 Firenze, Italy
| | - A Smerzi
- 1] LENS-Università di Firenze, Via Nello Carrara 1, 50019 Sesto Fiorentino, Italy [2] QSTAR, Largo Enrico Fermi 2, 50125 Firenze, Italy [3] Istituto Nazionale di Ottica, INO-CNR, Largo Enrico Fermi 2, 50125 Firenze, Italy
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Lombardi P, Schaefer F, Herrera I, Cherukattil S, Petrovic J, Lovecchio C, Marin F, Cataliotti FS. Reading the phase of a Raman excitation with a multi-state atomic interferometer. Opt Express 2014; 22:19141-19148. [PMID: 25321000 DOI: 10.1364/oe.22.019141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Atomic memories for flying photonic qubits are an essential ingredient for many applications like e.g. quantum repeaters. Verification of the coherent transfer of information from a light field to an atomic superposition is usually obtained using an optical read-out. In this paper we report the direct detection of the atomic coherence by means of atom interferometry. We experimentally verified both that a bichromatic laser field closing a Raman transition imprints a distinct, controllable phase on the atomic coherence and that it can be recovered after a variable time delay.
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Pontin A, Bonaldi M, Borrielli A, Cataliotti FS, Marino F, Prodi GA, Serra E, Marin F. Squeezing a thermal mechanical oscillator by stabilized parametric effect on the optical spring. Phys Rev Lett 2014; 112:023601. [PMID: 24484010 DOI: 10.1103/physrevlett.112.023601] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Indexed: 06/03/2023]
Abstract
We report the confinement of an optomechanical micro-oscillator in a squeezed thermal state, obtained by parametric modulation of the optical spring. We propose and implement an experimental scheme based on parametric feedback control of the oscillator, which stabilizes the amplified quadrature while leaving the orthogonal one unaffected. This technique allows us to surpass the -3 dB limit in the noise reduction, associated with parametric resonance, with a best experimental result of -7.4 dB. While the present experiment is in the classical regime, in a moderately cooled system our technique may allow squeezing of a macroscopic mechanical oscillator below the zero-point motion.
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Affiliation(s)
- A Pontin
- Istituto Nazionale di Fisica Nucleare (INFN), Gruppo Collegato di Trento, I-38123 Povo, Trento, Italy and Dipartimento di Fisica, Università di Trento, I-38123 Povo, Trento, Italy
| | - M Bonaldi
- Institute of Materials for Electronics and Magnetism, Nanoscience-Trento-FBK Division, 38123 Povo, Trento, Italy and INFN, Gruppo Collegato di Trento, Sezione di Padova, 38123 Povo, Trento, Italy
| | - A Borrielli
- Institute of Materials for Electronics and Magnetism, Nanoscience-Trento-FBK Division, 38123 Povo, Trento, Italy and INFN, Gruppo Collegato di Trento, Sezione di Padova, 38123 Povo, Trento, Italy
| | - F S Cataliotti
- Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino (FI), Italy and European Laboratory for Non-Linear Spectroscopy (LENS), Via Carrara 1, I-50019 Sesto Fiorentino (FI), Italy and INFN, Sezione di Firenze
| | - F Marino
- INFN, Sezione di Firenze and CNR-INO, L.go Enrico Fermi 6, I-50125 Firenze, Italy
| | - G A Prodi
- Istituto Nazionale di Fisica Nucleare (INFN), Gruppo Collegato di Trento, I-38123 Povo, Trento, Italy and Dipartimento di Fisica, Università di Trento, I-38123 Povo, Trento, Italy
| | - E Serra
- Istituto Nazionale di Fisica Nucleare (INFN), Gruppo Collegato di Trento, I-38123 Povo, Trento, Italy and Department of Microelectronics and Computer Engineering/ECTM/DIMES, Delft University of Technology, Feldmanweg 17, 2628 CT Delft, The Netherlands
| | - F Marin
- Dipartimento di Fisica e Astronomia, Università di Firenze, Via Sansone 1, I-50019 Sesto Fiorentino (FI), Italy and European Laboratory for Non-Linear Spectroscopy (LENS), Via Carrara 1, I-50019 Sesto Fiorentino (FI), Italy and INFN, Sezione di Firenze
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Fallani L, Cataliotti FS, Catani J, Fort C, Modugno M, Zawada M, Inguscio M. Optically induced lensing effect on a Bose-Einstein condensate expanding in a moving lattice. Phys Rev Lett 2003; 91:240405. [PMID: 14683097 DOI: 10.1103/physrevlett.91.240405] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2003] [Indexed: 05/24/2023]
Abstract
We report the experimental observation of a lensing effect on a Bose-Einstein condensate expanding in a moving 1D optical lattice. The effect of the periodic potential can be described by an effective mass dependent on the condensate quasimomentum. By changing the velocity of the atoms in the frame of the optical lattice, we induce a focusing of the condensate along the lattice direction. The experimental results are compared with the numerical predictions of an effective 1D theoretical model. In addition, a precise band spectroscopy of the system is carried out by looking at the real-space propagation of the atomic wave packet in the optical lattice.
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Affiliation(s)
- L Fallani
- European Laboratory for Non-Linear Spectroscopy (LENS), INFM and Dipartimento di Fisica, Università di Firenze, via Nello Carrara 1, I-50019 Sesto Fiorentino (FI), Italy.
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Fort C, Cataliotti FS, Fallani L, Ferlaino F, Maddaloni P, Inguscio M. Collective excitations of a trapped Bose-Einstein condensate in the presence of a 1D optical lattice. Phys Rev Lett 2003; 90:140405. [PMID: 12731902 DOI: 10.1103/physrevlett.90.140405] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2002] [Indexed: 05/24/2023]
Abstract
We study low-lying collective modes of an elongated 87Rb condensate produced in a 3D magnetic harmonic trap with the addition of a 1D periodic potential which is provided by a laser standing wave along the axial direction. While the transverse breathing mode remains unperturbed, quadrupole and dipole oscillations along the optical lattice are strongly modified. Precise measurements of the collective mode frequencies at different heights of the optical barriers provide a stringent test of the theoretical model recently introduced [M. Krämer, Phys. Rev. Lett. 88, 180404 (2002)]].
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Affiliation(s)
- C Fort
- LENS, Dipartimento di Fisica, Università di Firenze and Istituto Nazionale per la Fisica della Materia, via Nello Carrara 1, I-50019 Sesto Fiorentino (Florence), Italy
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Cataliotti FS, Fallani L, Ferlaino F, Fort C, Maddaloni P, Inguscio M. Dynamics of a trapped Bose Einstein condensate in the presence of a one-dimensional optical lattice. ACTA ACUST UNITED AC 2003. [DOI: 10.1088/1464-4266/5/2/353] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Pedri P, Pitaevskii L, Stringari S, Fort C, Burger S, Cataliotti FS, Maddaloni P, Minardi F, Inguscio M. Expansion of a coherent array of Bose-Einstein condensates. Phys Rev Lett 2001; 87:220401. [PMID: 11736388 DOI: 10.1103/physrevlett.87.220401] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2001] [Indexed: 05/23/2023]
Abstract
We investigate the properties of a coherent array containing about 200 Bose-Einstein condensates produced in a far detuned 1D optical lattice. The density profile of the gas, imaged after releasing the trap, provides information about the coherence of the ground-state wave function. The measured atomic distribution is characterized by interference peaks. The time evolution of the peaks, their relative population, as well as the radial size of the expanding cloud are in good agreement with the predictions of theory. The 2D nature of the trapped condensates and the conditions required to observe the effects of coherence are also discussed.
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Affiliation(s)
- P Pedri
- Dipartimento di Fisica, Università di Trento and Istituto Nazionale per la Fisica della Materia, I-38050 Povo, Italy
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Cataliotti FS, Scheunemann R, Hänsch TW, Weitz M. Superresolution of pulsed multiphoton Raman transitions. Phys Rev Lett 2001; 87:113601. [PMID: 11531522 DOI: 10.1103/physrevlett.87.113601] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2000] [Revised: 06/01/2001] [Indexed: 05/23/2023]
Abstract
We have investigated higher order multiphoton Raman resonances with two pulsed optical frequencies. Multiphoton transfer with up to 50 photons is observed with milliwatts of laser power. We demonstrate that the spectral width of the multiphoton resonances can be far below the Fourier transform linewidth of the driving optical pulses. The functional dependence of the transition linewidth on the number of exchanged photons is found to vary with the pulse shape. Our experiment is performed with laser-cooled rubidium atoms confined in a CO2-laser optical dipole trap.
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Affiliation(s)
- F S Cataliotti
- Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Strasse 1, 85748 Garching, Germany
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Cataliotti FS, Burger S, Fort C, Maddaloni P, Minardi F, Trombettoni A, Smerzi A, Inguscio M. Josephson junction arrays with Bose-Einstein condensates. Science 2001; 293:843-6. [PMID: 11486083 DOI: 10.1126/science.1062612] [Citation(s) in RCA: 688] [Impact Index Per Article: 29.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
We report on the direct observation of an oscillating atomic current in a one-dimensional array of Josephson junctions realized with an atomic Bose-Einstein condensate. The array is created by a laser standing wave, with the condensates trapped in the valleys of the periodic potential and weakly coupled by the interwell barriers. The coherence of multiple tunneling between adjacent wells is continuously probed by atomic interference. The square of the small-amplitude oscillation frequency is proportional to the microscopic tunneling rate of each condensate through the barriers and provides a direct measurement of the Josephson critical current as a function of the intermediate barrier heights. Our superfluid array may allow investigation of phenomena so far inaccessible to superconducting Josephson junctions and lays a bridge between the condensate dynamics and the physics of discrete nonlinear media.
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Affiliation(s)
- F S Cataliotti
- European Laboratory for Non-Linear Spectroscopy (LENS) and, Istituto Nationale per la Fisica della Materia (INFM), L.go E. Fermi 2, I-50125 Firenze, Italy
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Burger S, Cataliotti FS, Fort C, Minardi F, Inguscio M, Chiofalo ML, Tosi MP. Superfluid and dissipative dynamics of a Bose-Einstein condensate in a periodic optical potential. Phys Rev Lett 2001; 86:4447-4450. [PMID: 11384256 DOI: 10.1103/physrevlett.86.4447] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2001] [Indexed: 05/23/2023]
Abstract
We create Bose-Einstein condensates of 87Rb in a static magnetic trap with a superimposed blue-detuned 1D optical lattice. By displacing the magnetic trap center we are able to control the condensate evolution. We observe a change in the frequency of the center-of-mass oscillation in the harmonic trapping potential, in analogy with an increase in effective mass. For fluid velocities greater than a local speed of sound, we observe the onset of dissipative processes up to full removal of the superfluid component. A parallel simulation study visualizes the dynamics of the Bose-Einstein condensate and accounts for the main features of the observed behavior.
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Affiliation(s)
- S Burger
- INFM-LENS, Dipartimento di Fisica, Università di Firenze, Largo Enrico Fermi 2, I-50125 Firenze, Italia
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Fort C, Cataliotti FS, Prevedelli M, Inguscio M. Temperature-selective trapping of atoms in a dark state by means of quantum interference. Opt Lett 1997; 22:1107-1109. [PMID: 18185766 DOI: 10.1364/ol.22.001107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
We present a novel type of dark spontaneous-force optical trap. The trap is based on a velocity-selective inhibition of repumping light absorption produced by electromagnetically induced transparency. Accumulation of cold cesium atoms in a dark state is observed.
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Pavone FS, Bianchini G, Cataliotti FS, Hänsch TW, Inguscio M. Birefringence in electromagnetically induced transparency. Opt Lett 1997; 22:736-738. [PMID: 18185645 DOI: 10.1364/ol.22.000736] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
(4)He 2 (3)S(1) --> 2 (3)P transitions at 1083 nm were laser probed in the presence of radiation that coupled the 2 (3)P level with the 3 (3)S(1) level in a ladder scheme. The metastable helium that was used was produced in a rf discharge. Significant atomic birefringence was detected, in addition to complete electromagnetically induced transparency. A simple theoretical model explains the experimental results.
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Affiliation(s)
- F S Pavone
- European Laboratory for Non-linear Spectroscopy, Largo E. Fermi 2, Firenze, Italy
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