The Danish Center for Quantum Optics (QUANTOP) was established in 2001 at the Niels Bohr Institute.

  • Started as a DNRF "Center of Excellence" QUANTOP’s research is focused on exploring quantum effects at the interface between light and matter.
  • Our goal is to develop future quantum technologies based on superposition and entangled states of light and matter.

QUANTOP offers both specialized courses on the bachelor and master level as well as contributing to the overall teaching and research aims of the NBI.

 

Research at Quantop

At QUANTOP - the Quantum Optics Center – we study quantum effects at light-matter interface. Particles of light, photons, are great for creating, reading out and transmitting quantum information between material objects.

Quantum mechanics tells us that when light interacts with atoms they can become entangled, that is they exist in quantum superpositions.

Such entanglement, which the founding fathers of quantum mechanics considered its most fundamental and most controversial feature, is used at QUANTOP for breaking established limits in communication and sensing of fields and forces.

Teleportation of quantum states of objects, generation of single photons on demand, quantum memory for light, and measurements of fields and forces beyond the limit set by the Heisenberg uncertainty principle are among the experiments we perform.

Generation of quantum superposition states and entanglement requires extreme control of photons and material objects and careful protection from decoherence caused by the environment.

Various experimental techniques, including lasers, structured fibers, vacuum- and cryogenic setups and sensitive electronics have been developed to achieve such control.

Experiments with as diverse objects as room temperature atoms, cold atoms trapped around a nanofiber and high-Q mechanical membranes are carried out.

Our goal is to develop future quantum technologies based on superposition and entangled states of light and matter.

 

 

The center is funded by an ERC starting grant and DARPA, and the group is world leading in its research fields of quantum optics, atomic physics and optomechanics.

 

 

Publications 1997 - today

PhD theses by Quantop

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Phononically shielded photonic-crystal mirror membranes for cavity quantum optomechanics

G. Enzian, Z. Wang, A. Simonsen, J. Mathiassen, T. Vibel, Y. Tsaturyan, A. Tagantsev, A. Schliesser and E. S. Polzik
Opt. Express Vol. 31 (8) , pp. 13040   (2023)

Entanglement-Enhanced Magnetic Induction Tomography

W. Zheng, H. Wang, R. Schmieg, A. Oesterle and E. S. Polzik
Physical Review Letters Vol. 130 (20) , pp. 203602   (2023)

Two-colour high-purity Einstein-Podolsky-Rosen photonic state

T. B. Brasil, V. Novikov, H. Kerdoncuff, M. Lassen and E. S. Polzik
Nature Communications Vol. 13 (1)   (2022)

Prospects of a superradiant laser based on a thermal or guided beam of lessmml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"greaterlessmml:mmultiscriptsgreaterlessmml:migreaterSrless/mml:migreaterlessmml:mprescripts /greaterlessmml:none /greaterlessmml:mngreater88less/mml:mngreaterless/mml:mmultiscriptsgreaterless/mml:mathgreater

M. Tang, S. A. Schäffer and J. H. Müller
Physical Review A Vol. 106 (6) , pp. 063704   (2022)

Trajectories Without Quantum Uncertainties in Composite Systems with Disparate Energy Spectra

E. Zeuthen, E. S. Polzik and F. Y. Khalili
PRX Quantum Vol. 3 (2) , pp. 020362   (2022)

Room-temperature single-photon source with near-millisecond built-in memory

K. B. Dideriksen, R. Schmieg, M. Zugenmaier and E. S. Polzik
Nature Communications Vol. 12 (1)   (2021)

High-frequency broadband laser phase noise cancellation using a delay line

M. Parniak, I. Galinskiy, T. Zwettler and E. S. Polzik
Optics Express Vol. 29 (5) , pp. 6935   (2021)

Dissipative optomechanical coupling with a membrane outside of an optical cavity

A. K. Tagantsev and E. S. Polzik
Physical Review A Vol. 103 (6) , pp. 063503   (2021)

Cavity-immune spectral features in the pulsed superradiant crossover regime

M. Tang, S. A. Schäffer, A. A. Jørgensen, M. R. Henriksen, B. T. R. Christensen, J. H. Müller and J. W. Thomsen
Physical Review Research Vol. 3 (3) , pp. 033258   (2021)

Calibration of spin-light coupling by coherently induced Faraday rotation

R. A. Thomas, C. Østfeldt, C. Bærentsen, M. Parniak and E. S. Polzik
Optics Express Vol. 29 (15) , pp. 23637   (2021)

Single-Photon Source with Near-Millisecond Memory based on Room-Temperature Atomic Vapour

M. Zugenmaier, R. Schmieg, K. B. Dideriksen and E. S. Polzik
2021 Conference on Lasers and Electro-Optics Europe &ampmathsemicolon European Quantum Electronics Conference (CLEO/Europe-EQEC)   (2021)

Phonon counting thermometry of an ultracoherent membrane resonator near its motional ground state

I. Galinskiy, Y. Tsaturyan, M. Parniak and E. S. Polzik
Optica Vol. 7 (6) , pp. 718-725   (2020)

Double-Resonant Sum-Frequency Generation of Blue Light with Near-Unity Quantum Conversion Efficiency

H. Kerdoncuff, J. B. Christensen, T. B. Brasil, V. A. Novikov, E. Polzik, J. Hald and M. Lassen
Conference on Lasers and Electro-Optics   (2020)

Cavity-enhanced sum-frequency generation of blue light with near-unity conversion efficiency

H. Kerdoncuff, J. B. Christensen, T. B. Brasil, V. A. Novikov, E. S. Polzik, J. Hald and M. Lassen
Optics Express Vol. 28 (3) , pp. 3975   (2020)

Measurement and simulation of atomic motion in nanoscale optical trapping potentials

S. B. Markussen, J. Appel, C. Østfeldt, J.-B. S. Béguin, E. S. Polzik and J. H. Müller
Applied Physics B Vol. 126 (4)   (2020)

The Copenhagen Conference: Quantum Limits of Knowledge

E. S. Polzik
Quantum Studies: Mathematics and Foundations Vol. 7 (2) , pp. 195-195   (2020)

Entanglement between distant macroscopic mechanical and spin systems

R. A. Thomas, M. Parniak, C. Østfeldt, C. B. Møller, C. Bærentsen, Y. Tsaturyan, A. Schliesser, J. Appel, E. Zeuthen and E. S. Polzik
Nature Physics Vol. 17 (2) , pp. 228-233   (2020)

Detection of low-conductivity objects using eddy current measurements with an optical magnetometer

K. Jensen, M. Zugenmaier, J. Arnbak, H. Stærkind, M. V. Balabas and E. S. Polzik
Phys. Rev. Research Vol. 1 , pp. 033087   (2019)

Sensitive optomechanical transduction of electric and magnetic signals to the optical domain

A. Simonsen, S. A. Saarinen, J. D. Sanchez, J. H. Ardenkjær-Larsen, A. Schliesser and E. S. Polzik
Optics Express Vol. 27 (13) , pp. 18561   (2019)

Magnetic resonance imaging with optical preamplification and detection

A. Simonsen, J. D. Sánchez-Heredia, S. A. Saarinen, J. H. Ardenkjær-Larsen, A. Schliesser and E. S. Polzik
Scientific Reports Vol. 9 (1)   (2019)

Gravitational wave detection beyond the standard quantum limit using a negative-mass spin system and virtual rigidity

E. Zeuthen, E. S. Polzik and F. Y. Khalili
Phys. Rev. D Vol. 100 , pp. 062004   (2019)

Carrier-mediated optomechanical forces in semiconductor nanomembranes with coupled quantum wells

A. Barg, L. Midolo, G. Kirifmmode selse šfianskifmmode eelse ėfi, P. Tighineanu, T. Pregnolato, A. \c{c}. ç. ifmmode Ielse İfimamoifmmode gelse gfilu, P. Lodahl, A. Schliesser, S. Stobbe and E. S. Polzik
Phys. Rev. B Vol. 98 , pp. 155316   (2018)

Observation of Quantum Spin Noise in a 1D Light-Atoms Quantum Interface

J.-B. Béguin, J. H. Müller, J. Appel and E. S. Polzik
Phys. Rev. X Vol. 8 , pp. 031010   (2018)

Unconditional Steady-State Entanglement in Macroscopic Hybrid Systems by Coherent Noise Cancellation

X. Huang, E. Zeuthen, D. V. Vasilyev, Q. He, K. Hammerer and E. S. Polzik
Phys. Rev. Lett. Vol. 121 , pp. 103602   (2018)

Magnetocardiography on an isolated animal heart with a room-temperature optically pumped magnetometer

K. Jensen, M. A. Skarsfeldt, H. Stærkind, J. Arnbak, M. V. Balabas, S.-P. Olesen, B. H. Bentzen and E. S. Polzik
Scientific Reports Vol. 8 (1)   (2018)

Overcoming the Standard Quantum Limit in Gravitational Wave Detectors Using Spin Systems with a Negative Effective Mass

F. Y. Khalili and E. S. Polzik
Phys. Rev. Lett. Vol. 121 , pp. 031101   (2018)

Dissipative versus dispersive coupling in quantum optomechanics: Squeezing ability and stability

A. K. Tagantsev, I. V. Sokolov and E. S. Polzik
Phys. Rev. A Vol. 97 , pp. 063820   (2018)

Long-lived non-classical correlations towards quantum communication at room temperature

M. Zugenmaier, K. B. Dideriksen, A. S. Sørensen, B. Albrecht and E. S. Polzik
Communications Physics Vol. 1 (1)   (2018)

Quantum back-action-evading measurement of motion in a negative mass reference frame

C. B. Møller, R. A. Thomas, G. Vasilakis, E. Zeuthen, Y. Tsaturyan, M. Balabas, K. Jensen, A. Schliesser, K. Hammerer and E. S. Polzik
Nature Vol. 547 (7662) , pp. 191-195   (2017)

Multimode optomechanical system in the quantum regime

W. H. P. Nielsen, Y. Tsaturyan, C. B. Møller, E. S. Polzik and A. Schliesser
Proceedings of the National Academy of Sciences Vol. 114 (1) , pp. 62-66   (2017)

Ultracoherent nanomechanical resonators via soft clamping and dissipation dilution

Y. Tsaturyan, A. Barg, E. S. Polzik and A. Schliesser
Nature Nanotechnology Vol. 12 (8) , pp. 776-783   (2017)

Dipole force free optical control and cooling of nanofiber trapped atoms

C. Østfeldt, J.-B. S. Béguin, F. T. Pedersen, E. S. Polzik, J. H. Müller and J. Appel
Opt. Lett. Vol. 42 (21) , pp. 4315-4318   (2017)

Scalable photonic network architecture based on motional averaging in room temperature gas

J. Borregaard, M. Zugenmaier, J. M. Petersen, H. Shen, G. Vasilakis, K. Jensen, E. S. Polzik and A. S. Sørensen
Nature Communications Vol. 7 (1)   (2016)

Non-invasive detection of animal nerve impulses with an atomic magnetometer operating near quantum limited sensitivity

K. Jensen, R. Budvytyte, R. A. Thomas, T. Wang, A. M. Fuchs, M. V. Balabas, G. Vasilakis, L. D. Mosgaard, H. C. Stærkind, J. H. Müller, T. Heimburg, S.-P. Olesen and E. S. Polzik
Scientific Reports Vol. 6 (1)   (2016)

Entanglement and spin squeezing in a network of distant optical lattice clocks

E. S. Polzik and J. Ye
Phys. Rev. A Vol. 93 , pp. 021404   (2016)

Coherent Backscattering of Light Off One-Dimensional Atomic Strings

H. L. Sørensen, J.-B. Béguin, K. W. Kluge, I. Iakoupov, A. S. Sørensen, J. H. Müller, E. S. Polzik and J. Appel
Phys. Rev. Lett. Vol. 117 , pp. 133604   (2016)

A dynamic operation of a PIN photodiode

S. Okhonin, M. Gureev, D. Sallin, J. Appel, A. Koukab, A. Kvasov, M. Pastre, E. S. Polzik, A. K. Tagantsev, F. Uddegard and M. Kayal
Applied Physics Letters Vol. 106 (3) , pp. 031115   (2015)

Generation of a squeezed state of an oscillator by stroboscopic back-action-evading measurement

G. Vasilakis, H. Shen, K. Jensen, M. Balabas, D. Salart, B. Chen and E. S. Polzik
Nature Physics Vol. 11 (5) , pp. 389-392   (2015)

Optical detection of radio waves through a nanomechanical transducer

T. Bağcı, A. Simonsen, S. Schmid, L. Villanueva, E. Zeuthen, J. Appel, J. Taylor, A. Sørensen, K. Usami, A. Schliesser and E. Polzik
Nature Vol. 507 , pp. 81-85   (2014)

Generation and Detection of a Sub-Poissonian Atom Number Distribution in a One-Dimensional Optical Lattice

J.-B. Béguin, E. M. Bookjans, S. L. Christensen, H. L. Sørensen, J. H. Müller, E. S. Polzik and J. Appel
Phys. Rev. Lett. Vol. 113 , pp. 263603   (2014)

Quantum interference of a single spin excitation with a macroscopic atomic ensemble

S. Christensen, J.-B. Béguin, E. Bookjans, H. Sørensen, J. Müller, J. Appel and E. Polzik
Phys. Rev. A Vol. 89 (3) , pp. 033801   (2014)

Heater self-calibration technique for shape prediction of fiber tapers

H. L. Sørensen, E. S. Polzik and J. Appel
J. Lightwave. Technol. Vol. 32 (10) , pp. 1886-1891   (2014)

Demonstration of suppressed phonon tunneling losses in phononic bandgap shielded membrane resonators for high-Q optomechanics

Y. Tsaturyan, A. Barg, A. Simonsen, L. G. Villanueva, S. Schmid, A. Schliesser and E. S. Polzik
Optics Express Vol. 22 (6) , pp. 6810   (2014)

Towards quantum state tomography of a single polariton state of an atomic ensemble

S. L. Christensen, J. B. Béguin, H. L. Sørensen, E. Bookjans, D. Oblak, J. H. Müller, J. Appel and E. Polzik
New Journal of Physics, Focus issue on Quantum Tomography Vol. 15 (1) , pp. 015002   (2013)

Deterministic quantum teleportation between distant atomic objects

H. Krauter, D. Salart, C. Muschik, J. M. Petersen, H. Shen, T. Fernholz and E. Polzik
Nature Physics   (2013)

In-Situ Dual-Port Polarization Contrast Imaging of Faraday Rotation in a High Optical Depth Ultracold 87Rb Atomic Ensemble

F. Kaminski, N. Kampel, M. Steenstrup, A. Griesmaier, E. Polzik and J. Müller
European Journal of Physics D Vol. 66 , pp. 227   (2012)

Atomic nonclassicality quasiprobabilities

T. Kiesel, W. Vogel, S. Christensen, J.-B. Béguin, J. Appel and E. Polzik
Phys. Rev. A Vol. 86 , pp. 042108   (2012)

Evading Quantum Mechanics: Engineering a Classical Subsystem within a Quantum Environment

M. Tsang and C. M. Caves
Physical Review X Vol. 2 (3)   (2012)

Quantum memory for entangled continuous-variable states

K. Jensen, W. Wasilewski, H. Krauter, T. Fernholz, B. Nielsen, M. Owari, M. Plenio, A. Serafini, M. Wolf and E. Polzik
Nature Physics Vol. 7 , pp. 13-16   (2011)

Entanglement Generated by Dissipation and Steady State Entanglement of Two Macroscopic Objects

H. Krauter, C. Muschik, K. Jensen, W. Wasilewski, J. Petersen, J. Cirac and E. Polzik
Phys. Rev. Lett. Vol. 107 (8) , pp. 080503-+   (2011)

Entanglement Generated by Dissipation

C. Muschik, H. Krauter, K. Jensen, W. Wasilewski, J. M. Petersen, I. Cirac and E. Polzik
International Conference on Quantum Information International Conference on Quantum Information, pp. QMH1   (2011)

Fock-state view of weak-value measurements and implementation with photons and atomic ensembles

C. Simon and E. Polzik
Phys. Rev. A Vol. 83 (4) , pp. 040101   (2011)

Mesoscopic Non-classical Atomic States for Quantum Information and Metrology

J. Appel, J. Renema, D. Oblak, A. Louchet-Chauvet, N. Kjærgaard and E. Polzik
(September) Latin America Optics and Photonics Conference   (2010)

High quality anti-relaxation coating material for alkali atom vapor cells

M. V. Balabas, K. Jensen, W. Wasilewski, H. Krauter, L. S. Madsen, J. H. Müller, T. Fernholz and E. S. Polzik
Opt. Express Vol. 18 (6) , pp. 5825-5830   (2010)

Quantum interface between light and atomic ensembles

K. Hammerer, A. Sørensen and E. Polzik
Rev. Mod. Phys. Vol. 82 , pp. 1041-1093   (2010)

Quantum state transfer between light and matter via teleportation

H. Krauter, J. Sherson and E. Polzik
Laser & Photonics Reviews Vol. 4 (6) , pp. 685-696   (2010)

Entanglement-assisted atomic clock beyond the projection noise limit

A. Louchet-Chauvet, J. Appel, J. Renema, D. Oblak, N. Kjærgaard and E. Polzik
New. J. Phys. Vol. 12 (6) , pp. 065032-+   (2010)

Quantum memories. A review based on the European integrated project `Qubit Applications (QAP)'

C. Simon, M. Afzelius, J. Appel, A. Boyer de La Giroday, S. Dewhurst, N. Gisin, C. Hu, F. Jelezko, S. Kröll, J. Müller, J. Nunn, E. Polzik, J. Rarity, H. de Riedmatten, W. Rosenfeld, A. Shields, N. Sköld, R. Stevenson, R. Thew, I. Walmsley, M. Weber, H. Weinfurter, J. Wrachtrup and R. Young
European Physical Journal D Vol. 58 , pp. 1-22   (2010)

Optoelectronic cooling of mechanical modes in a semiconductor nanomembrane

K. Usami, A. Naesby, T. Bagci, B. Nielsen, J. Liu, S. Stobbe, P. Lodahl and E. Polzik
  (2010)

Quantum volume hologram

D. Vasilyev, I. Sokolov and E. Polzik
Physical Review A Vol. 81 (2) , pp. 020302-+   (2010)

Quantum Noise Limited and Entanglement-Assisted Magnetometry

W. Wasilewski, K. Jensen, H. Krauter, J. Renema, M. Balabas and E. Polzik
Phys. Rev. Lett. Vol. 104 (13) , pp. 133601-+   (2010)

A versatile digital GHz phase lock for external cavity diode lasers

J. Appel, A. MacRae and A. Lvovsky
Measurement Science and Technology Vol. 20 (5) , pp. 055302-+   (2009)

Mesoscopic atomic entanglement for precision measurements beyond the standard quantum limit

J. Appel, P. Windpassinger, D. Oblak, U. Busk Hoff, N. Kjærgaard and E. Polzik
P. Natl. Acad. Sci. Vol. 106 , pp. 10960-10965   (2009)

Establishing Einstein-Poldosky-Rosen Channels between Nanomechanics and Atomic Ensembles

K. Hammerer, M. Aspelmeyer, E. Polzik and P. Zoller
Physical Review Letters Vol. 102 (2) , pp. 020501-+   (2009)

Cavity-assisted squeezing of a mechanical oscillator

K. Jähne, C. Genes, K. Hammerer, M. Wallquist, E. Polzik and P. Zoller
Physical Review A Vol. 79 (6) , pp. 063819-+   (2009)

Cancellation of nonlinear Zeeman shifts with light shifts

K. Jensen, V. Acosta, J. Higbie, M. Ledbetter, S. Rochester and D. Budker
Physical Review A Vol. 79 (2) , pp. 023406-+   (2009)

Polarization-based light-atom quantum interface with an all-optical trap

M. Kubasik, M. Koschorreck, M. Napolitano, S. de Echaniz, H. Crepaz, J. Eschner, E. Polzik and M. Mitchell
Physical Review A Vol. 79 (4) , pp. 043815-+   (2009)

Experimental quantum key distribution with proven security against realistic attacks

P. Nielsen, C. Schori, J. Sørensen, L. Salvail, I. Damgard and E. Polzik
Journal of Modern Optics Vol. 48 (13) , pp. 1921-1942   (2009)

Quantum polarization spectroscopy of correlations in attractive fermionic gases

T. Roscilde, M. Rodríguez, K. Eckert, O. Romero-Isart, M. Lewenstein, E. Polzik and A. Sanpera
New Journal of Physics Vol. 11 (5) , pp. 055041-+   (2009)

Spin squeezing of atomic ensembles by multicolor quantum nondemolition measurements

M. Saffman, D. Oblak, J. Appel and E. Polzik
Phys. Rev. A Vol. 79 (2) , pp. 023831-+   (2009)

Generation of two-mode squeezed and entangled light in a single temporal and spatial mode

W. Wasilewski, T. Fernholz, K. Jensen, L. Madsen, H. Krauter, C. Muschik and E. Polzik
Optics Express Vol. 17 , pp. 14444-+   (2009)

Ultra low-noise differential ac-coupled photodetector for sensitive pulse detection applications

P. Windpassinger, M. Kubasik, M. Koschorreck, A. Boisen, N. Kjærgaard, E. Polzik and J. Müller
Measurement Science and Technology Vol. 20 (5) , pp. 055301-+   (2009)

Squeezing of atomic quantum projection noise

P. J. Windpassinger, D. Oblak, U. Busk Hoff, A. Louchet, J. Appel, N. Kjaergaard and E. S. Polzik
Journal Of Modern Optics Vol. 56 (18-19) , pp. 1993-1998   (2009)

Quantum non-demolition detection of strongly correlated systems

K. Eckert, O. Romero-Isart, M. Rodriguez, M. Lewenstein, E. Polzik and A. Sanpera
Nature Physics Vol. 4 , pp. 50-54   (2008)

Spin Squeezing of Atomic Ensembles via Nuclear-Electronic Spin Entanglement

T. Fernholz, H. Krauter, K. Jensen, J. F. Sherson, A. S. Sørensen and E. S. Polzik
Phys. Rev. Lett. Vol. 101 (7) , pp. 073601   (2008)

Rayleigh superradiance and dynamic Bragg gratings in an end-pumped Bose-Einstein condensate

A. Hilliard, F. Kaminski, R. Le Targat, C. Olausson, E. Polzik and J. Müller
Physical Review A Vol. 78 (5) , pp. 051403-+   (2008)

Quantum Interface between Light and Atomic Ensembles

H. Krauter, J. Sherson, K. Jensen, T. Fernholz, J. Neergaard-Nielsen, B. Nielsen, D. Oblak, P. Windpassinger, N. Kjærgaard, A. Hilliard, C. Olausson, J. Müller and E. Polzik
(XVIII) Laser Spectroscopy, pp. 113-124   (2008)

Detecting entanglement in two mode squeezed states by particle counting

C. Muschik, E. Polzik and J. Cirac
ArXiv e-prints   (2008)

Echo spectroscopy of atomic dynamics in a Gaussian trap via phase imprints

D. Oblak, J. Appel, P. Windpassinger, U. Busk Hoff, N. Kjærgaard and E. Polzik
European Physical Journal D Vol. 50 , pp. 67-73   (2008)

Squeezing the limit: quantum benchmarks for the teleportation and storage of squeezed states

M. Owari, M. Plenio, E. Polzik, A. Serafini and M. Wolf
New Journal of Physics Vol. 10 (11) , pp. 113014-+   (2008)

Quantum physics: The squeeze goes on

E. Polzik
Nature Vol. 453 , pp. 45-46   (2008)

Quantum memory for images: A quantum hologram

D. Vasilyev, I. Sokolov and E. Polzik
Physical Review A Vol. 77 (2) , pp. 020302-+   (2008)

Inhomogeneous light shift effects on atomic quantum state evolution in non-destructive measurements

P. Windpassinger, D. Oblak, U. Busk Hoff, J. Appel, N. Kjærgaard and E. Polzik
New. J. Phys. Vol. 10 (5) , pp. 053032-+   (2008)

Nondestructive Probing of Rabi Oscillations on the Cesium Clock Transition near the Standard Quantum Limit

P. Windpassinger, D. Oblak, P. Petrov, M. Kubasik, M. Saffman, C. Alzar, J. Appel, J. Müller, N. Kjærgaard and E. Polzik
Physical Review Letters Vol. 100 (10) , pp. 103601-+   (2008)

Quantum Polarization Spectroscopy of Ultracold Spinor Gases

K. Eckert, Ł. Zawitkowski, A. Sanpera, M. Lewenstein and E. Polzik
Physical Review Letters Vol. 98 (10) , pp. 100404-+   (2007)

Spectral theory of quantum memory and entanglement via Raman scattering of light by an atomic ensemble

O. Mishina, D. Kupriyanov, J. Müller and E. Polzik
Physical Review A Vol. 75 (4) , pp. 042326-+   (2007)

High purity bright single photon source

J. Neergaard-Nielsen, B. Nielsen, H. Takahashi, A. Vistnes and E. Polzik
Optics Express Vol. 15 , pp. 7940-7949   (2007)

Nondestructive interferometric characterization of an optical dipole trap

P. Petrov, D. Oblak, C. Alzar, N. Kjærgaard and E. Polzik
Physical Review A Vol. 75 (3) , pp. 033803-+   (2007)

Single-passage readout of atomic quantum memory

J. Fiurášek, J. Sherson, T. Opatrný and E. Polzik
Physical Review A Vol. 73 (2) , pp. 022331-+   (2006)

High-fidelity teleportation between light and atoms

K. Hammerer, E. S. Polzik and J. I. Cirac
Physical Review A Vol. 74 (6) , pp. 064301   (2006)

Macroscopic quantum information channel via the polarization-sensitive interaction between the light and spin subsystems

O. Mishina, E. Polzik and D. Kupriyanov
Vol. 199 Quantum information processing from theory to experiment, pp. 346-352   (2006)

Efficient quantum memory and entanglement between light and an atomic ensemble using magnetic fields

C. Muschik, K. Hammerer, E. Polzik and J. Cirac
Physical Review A Vol. 73 (6) , pp. 062329-+   (2006)

Generation of a Superposition of Odd Photon Number States for Quantum Information Networks

J. S. Neergaard-Nielsen, B. M. Nielsen, C. Hettich, K. Mølmer and E. S. Polzik
Phys. Rev. Lett. Vol. 97 (8) , pp. 083604   (2006)

Deterministic Atom-Light Quantum Interface

J. Sherson, B. Julsgaard and E. S. Polzik
Vol. 54 Advances In Atomic, Molecular, and Optical Physics, pp. 81-130   (2006)

Light qubit storage and retrieval using macroscopic atomic ensembles

J. Sherson, A. Sørensen, J. Fiurášek, K. Mølmer and E. Polzik
Physical Review A Vol. 74 (1) , pp. 011802-+   (2006)

Quantum teleportation between light and matter

J. F. Sherson, H. Krauter, R. K. Olsson, B. Julsgaard, K. Hammerer, I. Cirac and E. S. Polzik
Nature Vol. 443 , pp. 557-560   (2006)

Conditions for spin squeezing in a cold^87Rb ensemble

S. de Echaniz, M. Mitchell, M. Kubasik, M. Koschorreck, H. Crepaz, J. Eschner and E. Polzik
Journal of Optics B: Quantum and Semiclassical Optics Vol. 7 , pp. 548-+   (2005)

Teleportation and spin squeezing utilizing multimode entanglement of light with atoms

K. Hammerer, E. Polzik and J. Cirac
Physical Review A Vol. 72 (5) , pp. 052313-+   (2005)

Quantum Benchmark for Storage and Transmission of Coherent States

K. Hammerer, M. M. Wolf, E. S. Polzik and J. I. Cirac
Physical Review Letters Vol. 94 (15) , pp. 150503   (2005)

Multimode entanglement of light and atomic ensembles via off-resonant coherent forward scattering

D. Kupriyanov, O. Mishina, I. Sokolov, B. Julsgaard and E. Polzik
Physical Review A Vol. 71 (3) , pp. 032348-+   (2005)

Diffraction effects on light-atomic-ensemble quantum interface

J. Müller, P. Petrov, D. Oblak, C. Garrido Alzar, S. de Echaniz and E. Polzik
Phys. Rev. A Vol. 71 (3) , pp. 033803-+   (2005)

Quantum-noise-limited interferometric measurement of atomic noise: Towards spin squeezing on the Cs clock transition

D. Oblak, P. Petrov, C. Garrido Alzar, W. Tittel, A. Vershovski, J. Mikkelsen, J. Sørensen and E. Polzik
Physical Review A Vol. 71 (4) , pp. 043807-+   (2005)

Quantum interface between light and atomic ensembles

E. Polzik and J. Fiurášek
Lectures on Quantum Information, pp. 515-534   (2005)

Distant entanglement of macroscopic gas samples

J. Sherson, B. Julsgaard and E. Polzik
Decoherence, Entanglement and Information Protection in Complex Quantum Systems Vol. 189 (V) Decoherence, Entanglement and Information Protection in Complex Quantum Systems, pp. 353-372   (2005)

Quantum information processing and communication. Strategic report on current status, visions and goals for research in Europe

P. Zoller, T. Beth, D. Binosi, R. Blatt, H. Briegel, D. Bruss, T. Calarco, J. Cirac, D. Deutsch, J. Eisert, A. Ekert, C. Fabre, N. Gisin, P. Grangiere, M. Grassl, S. Haroche, A. Imamoglu, A. Karlson, J. Kempe, L. Kouwenhoven, S. Kröll, G. Leuchs, M. Lewenstein, D. Loss, N. Lütkenhaus, S. Massar, J. Mooij, M. Plenio, E. Polzik, S. Popescu, G. Rempe, A. Sergienko, D. Suter, J. Twamley, G. Wendin, R. Werner, A. Winter, J. Wrachtrup and A. Zeilinger
European Physical Journal D Vol. 36 , pp. 203-228   (2005)

Quantum Cloning of a Coherent Light State into an Atomic Quantum Memory

J. Fiurášek, N. Cerf and E. Polzik
Physical Review Letters Vol. 93 (18) , pp. 180501-+   (2004)

Light-matter quantum interface

K. Hammerer, K. Mølmer, E. Polzik and J. Cirac
Physical Review A Vol. 70 (4) , pp. 044304-+   (2004)

Experimental demonstration of quantum memory for light

B. Julsgaard, J. Sherson, J. I. Cirac, J. Fiurášek and E. S. Polzik
Nature Vol. 432 , pp. 482-486   (2004)

Characterizing the spin state of an atomic ensemble using the magneto-optical resonance method

B. Julsgaard, J. Sherson, J. Sørensen and E. Polzik
Journal of Optics B: Quantum and Semiclassical Optics Vol. 6 , pp. 5-14   (2004)

Atomic spins as a storage medium for quantum fluctuations of light

B. Julsgaard, C. Schori, J. L. Sørensen and E. S. Polzik
Quantum Info. Comput. Vol. 3 , pp. 518-534   (2003)

Generating a Superposition of Spin States in an Atomic Ensemble

S. Massar and E. Polzik
Physical Review Letters Vol. 91 (6) , pp. 060401-+   (2003)

Entanglement and quantum teleportation with multi-atom ensembles

E. Polzik, B. Julsgaard and J. Sherson
Royal Society of London Philosophical Transactions Series A Vol. 361 , pp. 1391-1399   (2003)

Quantum limits encountered in atomic spin measurements

J. Sørensen, B. Julsgaard, C. Schori and E. S. Polzik
Spectrochimica Acta Vol. 58 , pp. 999-1010   (2003)

Quantum Noise Limited Laser Probing of Atomic Spin States

J. Sørensen, B. Julsgaard, C. Schori, J. Hald and E. Polzik
Laser Physics Vol. 13 (3) , pp. 359-367   (2003)

Atomic entanglement on a grand scale

E. Polzik
Physics World Vol. 15 (9) , pp. 33-37   (2002)

Recording Quantum Properties of Light in a Long-Lived Atomic Spin State: Towards Quantum Memory

C. Schori, B. Julsgaard, J. Sørensen and E. Polzik
Physical Review Letters Vol. 89 (5) , pp. 057903-+   (2002)

Narrow-band frequency tunable light source of continuous quadrature entanglement

C. Schori, J. Sørensen and E. Polzik
Physical Review A Vol. 66 (3) , pp. 033802-+   (2002)

Mapping a quantum state of light onto atoms

J. Hald and E. Polzik
Journal of Optics B: Quantum and Semiclassical Optics Vol. 3 , pp. 83-+   (2001)

Experimental long-lived entanglement of two macroscopic objects

B. Julsgaard, A. Kozhekin and E. S. Polzik
Nature Vol. 413 , pp. 400-403   (2001)

Quantum Communication between Atomic Ensembles Using Coherent Light

L.-M. Duan, J. Cirac, P. Zoller and E. Polzik
Physical Review Letters Vol. 85 , pp. 5643-5646   (2000)

Entanglement transfer from light to atoms

J. Hald, J. L. Sørensen, C. Schori and E. S. Polzik
Journal of Modern Optics Vol. 47 (14-15) , pp. 2000   (2000)

Quantum memory for light

A. E. Kozhekin, K. Mølmer and E. Polzik
Physical Review A Vol. 62 (3) , pp. 033809   (2000)

Atomic Quantum State Teleportation and Swapping

A. Kuzmich and E. Polzik
Physical Review Letters Vol. 85 , pp. 5639-5642   (2000)

Spin Squeezed Atoms: A Macroscopic Entangled Ensemble Created by Light

J. Hald, J. L. Sørensen, C. Schori and E. S. Polzik
Phys. Rev. Lett. Vol. 83 (7) , pp. 1319-1322   (1999)

Einstein-Podolsky-Rosen-correlated atomic ensembles

E. Polzik
Physical Review A Vol. 59 , pp. 4202-4205   (1999)

Unconditional Quantum Teleportation

A. Furusawa, J. Sørensen, S. Braunstein, C. Fuchs, H. Kimble and E. Polzik
Science Vol. 282 , pp. 706-+   (1998)

Quantum Noise of an Atomic Spin Polarization Measurement

J. Sørensen, J. Hald and E. Polzik
Physical Review Letters Vol. 80 , pp. 3487-3490   (1998)

Spin Squeezing in an Ensemble of Atoms Illuminated with Squeezed Light

A. Kuzmich, K. Mølmer and E. S. Polzik
Physical Review Letters Vol. 79 (24) , pp. 4782-4785   (1997)

 

 

We are always looking for motivated and dedicated students with an interest in quantum mechanics, atomic physics, optomechanics, quantum memories laser physics, quantum information. 

Please contact Prof. Eugene Polzik at polzik*nbi.dk if you are interested.

  • Bachelor Project opportunities
    Please contact Prof. Eugene Polzik at polzik*nbi.dk if you are interested.
  • Master Project opportunities
    Please contact Prof. Eugene Polzik at polzik*nbi.dk if you are interested.
  • PhD positions
    Please contact Prof. Eugene Polzik at polzik*nbi.dk if you are interested.
  • PostDoc positions
    Please contact Prof. Eugene Polzik at polzik*nbi.dk if you are interested.

 

 

Accommodations

Short-term accommodation

In case you are making your own arrangements, here is a list including links to nearby hotels and hostels offering private rooms. Please note that the rates are approximate and reflect a single standard rooms with no breakfast included. 

 Hotel name

Approx rate

Distance to NBI 

Hotel 9 smaa hjem (apartment-style)

800 DKK

1.0 km

Hotel Kong Arthur

 1100 DKK 

 1.3 km 

Ibsens Hotel

 1000 DKK 

 1.3 km 

Generator Hostel

  from 400 DKK 

 1.8 km 

Hotel Guldsmeden Babette

1100 DKK 

1.2 km 

Hotel Guldsmeden Carlton

 1100 DKK 

3.0 km 

CabInn Express

 800 DKK 

 3.0 km 


We have also had good experiences with AirBnB for rooms or full apartments - if you go that route, note that Nørrebro (Copehnagen N), Østerbro (Copenhagen Ø) and Copenhagen City/downtown are the neighborhoods closest to the NBI, though any Copenhagen or Frederiksberg address will be close on bike or public transport.

Apartments and other longer-term accomodation

If you are coming with family or staying more than a few days and are interested in renting an apartment or would like to stay in a university student Kollegium (studio apartment), let us know, and we will advise on the possibilities. If you are a new staff member moving to Copenhagen, consult the University Housing Foundation for help, and feel free to let us know if you need further assistance.

 

 

The Niels Bohr institute has many M.Sc. and PhD students. The students are closely attached to the research groups and supervisor, and have many social activities for International and Danish students.

If you are interested in studying Quantum Optics, consider looking at these pages:

 

 

QUANTOP, Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, 2100 Copenhagen Ø. Denmark.

Prof. Eugene PolzikDirector:

Prof. Eugene Polzik
Office phone: 3532 5424
Cell phone: 2338 2045
Email: polzik@nbi.dk

 

Charlotte HviidAdministration:

Charlotte Hviid
Office: Bygning T, Ta2a
Office phone: +45 35325254
E-mail: hviid@nbi.ku.dk

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