## QuantERA project: Photon-Atom Cooperative Effects at Interfaces (PACE-IN)

Functional devices for**quantum information processing and communication**must make use of appropriate matter-light interfaces. Their key role in bringing quantum devices towards practical applications is essential. Hence, building the conceptual and technological base for such interfaces will pave the way for the scalable quantum computation and quantum Internet. The overall objective of this proposal is to meet the critical challenge of studying, implementing and optimizing ground-breaking,

**dynamically-controlled interfaces between matter and light**.

Photons can efficiently and durably transmit quantum information over large distances; cold, trapped ions can be manipulated to enable high-fidelity quantum information processing, while atomic ensembles are particularly suited for long-lived quantum memories, as well as nonlinear generation of non-classical correlations between optical beams. The aim of the PACE-IN project is the development of r

**eliable quantum interfaces between atomic systems and photons**. We shall develop and demonstrate massive parallel processing, storage and transmission of quantum information by hitherto unexploited collective, multimode quantum states or atomic ensembles and ionic crystals, and design methods to characterize the entanglement and non-classicality of quantum states transferred from atoms and ions to photons.

Efficient interfacing mechanisms between “stationary” atomic qubits or ensembles and “flying” (photonic) quantum variables, whether discrete or continuous, must be robust and dynamically controllable to allow the best possible exploitation of their respective functionalities while maintaining the highest possible overall fidelity/coherence and speed. The scientific and technological challenge that will be addressed in this project is the conceptually and experimentally optimized quantum information processing and manipulation at interfaces for the successful implementation of scalable quantum technologies in combination with long distance quantum communication.

This European collaborative project is funded by each national research agency in the framework of the QuantERA program. It started in April 2020 and will end in June 2024.

### News & events

## April 2024: Visit of Viviana Viggiano in Nice

Vivianna Viggiano, a PhD student at Univ. Bari, visited the Nice group for a few weeks. She collaborates with Robin Kaiser on the theory of cooperative scattering.

## Oct. 2023: Workshop in Crete

The PACE-IN consortium organized a joint workshop with other partners on "Quantum and Collective Phenomena in Light-Matter Interactions". See the dedicated website. This has been a great event!

## July 2022: Visit of Lukáš Slodička in Nice

Lukáš, from the Olomouc group, visited the Nice group for a few weeks. He collaborated with Mathilde Hugbart on the measurement of intensity-field correlations.

## Nov. 2021: Colloquium by R. Kaiser at Aarhus

Presentation by Robin Kaiser at Aarhus University, invited by Klaus Mølmer.

## Oct. 2021: The PACE-IN webpage is back!

After several months of interruption and the complete loss of data (due to the fire of the data center), the PACE-IN webpage is finally back. But this is still a work in progress...

### Consortium

- Institut de Physique de Nice (CNRS, UCA, France)
- Universität Innsbruck (Austria)
- FORTH (Greece)
- Weizmann Institute (Israel)
- INFN (Bari, Italy)
- Palacký University (Olomouc, Czech Rep.)

**External Advisory Committee:**Klaus Mølmer (Aarhus University) and Jörg Schmiedmayer (TU Wien).

### Publications

**Condensation of vanishing photon emission rates in random atomic clouds**

V. Viggiano, R. Bachelard, F. D. Cunden, P. Facchi, R. Kaiser, S. Pascazio, F. V. Pepe, A. Scardicchio

Preprint: arXiv:2407.11858

**Quantum bistability at the interplay between collective and individual decay**

N. Leppenen and E. Shahmoon,

Preprint: arXiv:2404.02134

**Quantum interfaces with multilayered superwavelength atomic arrays**

R. Ben-Maimon, Y. Solomons, N. Davidson, O. Firstenberg, and E. Shahmoon

Preprint: arXiv:2402.06839

**Spin projection noise and the magnetic sensitivity of optically pumped magnetometers**

K. Mouloudakis, V. Koutrouli, I. K. Kominis, M. W. Mitchell, G. Vasilakis

Preprint: arXiv:2402.10746

**Breaking of reciprocity and the Pancharatnam-Berry phase for light scattered by a disordered cold atom cloud**

P. H. N. Magnani, P. G. S. Dias, M. Frometa, M. A. Martins, N. Piovella, R. Kaiser, Ph. W. Courteille, M. Hugbart, R. Bachelard, R. C. Teixeira

Preprint: arXiv:2401.05297

**Coupling light to an atomic tweezer array in a cavity**

Y. Solomons, I. Shani, O. Firstenberg, N. Davidson, and E. Shahmoon

Preprint: arXiv:2312.11104

**Dissipative transfer of quantum correlations from light to atomic arrays**

R. Ben-Maimon, Y. Solomons and E. Shahmoon

Preprint: arXiv:2311.03898

**Qubit analog with polariton superfluid in an annular trap**

J. Barrat, A. F. Tzortzakakis, M. Niu, X. Zhou, G.G. Paschos, D. Petrosyan, P.G. Savvidis

Preprint: arXiv:2308.05555

**Detecting entanglement from macroscopic measurements of the electric field and its fluctuations**

P. Rosario, A. C. Santos, N. Piovella, R. Kaiser, A. Cidrim, R. Bachelard

Phys. Rev. Lett., in press (2024), preprint: arXiv:2404.15973

**Temporal coherences of atomic chaotic light sources: the Siegert relation and beyond**

M. Morisse, S. Joshi, J. Mika, J. Capella, R. Kaiser, R. Bachelard, L. Slodicka, M. Hugbart

Europhys. Lett., in press (2024), preprint: arXiv:2404.01711

**A chiral quantum router with Rydberg atoms**

N. E. Palaiodimopoulos, S. Ohler, M. Fleischhauer, D. Petrosyan

Phys. Rev. A**109**, 032622 (2024)

**Coherent interface between optical and microwave photons on an integrated superconducting atom chip**

D. Petrosyan, J. Fortágh, G. Kurizki,

EPJ Quantum Technology**11**, 18 (2024)

**Universal approach for quantum interfaces with atomic arrays**

Y. Solomons, R. Ben-Maimon and E. Shahmoon

PRX Quantum**5**, 020329 (2024)

**Quantum entangled states of a classically radiating macroscopic spin**

O. Somech and E. Shahmoon

PRX Quantum**5**, 010349 (2024)

**Thermal transitions in a one-dimensional, finite-size Ising model**

V. Stepanyan, A. F. Tzortzakakis, D. Petrosyan, A. E. Allahverdyan

J. Stat. Mech.**2024**, 033202 (2024)

**Black-hole powered quantum coherent amplifier**

A. Misra, P. Chattopadhyay, A. Svidzinsky, M. O. Scully and G. Kurizki

npj Quant. Info.**10**, 34 (2024)

**Sensing microscopic noise events by frequent quantum measurements**

S. Virzì, Laura T. Knoll, A. Avella, F. Piacentini, S. Gherardini, M. Gramegna, G. Kurizki, A. G. Kofman, I. Pietro Degiovanni, M. Genovese, F. Caruso

Phys. Rev. Appl.**21**, 034014 (2024)

**Super- and subradiance in dilute disordered cold atomic samples: observations and interpretations**

W. Guerin

in*Advances in Atomic, Molecular and Optical Physics, vol. 72*, 2023, pages 253-296

Edited by L. DiMauro, H. Perrin, and S. Yelin (Elsevier)

Preprint: arXiv:2306.02891

**Cooperative photon emission rates in random atomic clouds**

V. Viggiano, R. Bachelard, F. D. Cunden, P. Facchi, R. Kaiser, S. Pascazio, F. V. Pepe

Phys. Rev. A**108**, 063701 (2023), preprint: arXiv:2306.06055

**From classical to quantum loss of light coherence**

P. Lassègues, M. A. F. Biscassi, M. Morisse, A. Cidrim, P. G. S. Dias, H. Eneriz, R. Celistrino Teixeira, R. Kaiser, R. Bachelard, M. Hugbart

Phys. Rev. A**108**, 042214 (2023), preprint: arXiv:2210.01003

Editors' Suggestion

**Excitation transfer in disordered spin chains with long-range exchange interactions**

N. E. Palaiodimopoulos, M. Kiefer-Emmanouilidis, G. Kurizki, D. Petrosyan

SciPost Phys. Core**6**, 017 (2023)

**Interspecies spin-noise correlations in hot atomic vapors**

K. Mouloudakis, F. Vouzinas, A. Margaritakis, A. Koutsimpela, G. Mouloudakis, V. Koutrouli, M. Skotiniotis, G. P. Tsironis, M. Loulakis, M. W. Mitchell, G. Vasilakis, and I. K. Kominis

Phys. Rev. A**108**, 052822 (2023)

**Heisenberg-Langevin approach to driven superradiance**

O. Somech, Y. Shimshi and E. Shahmoon

Phys. Rev. A**108**, 023725 (2023)

**Multi-channel waveguide QED with atomic arrays in free space**

Y. Solomons and E. Shahmoon

Phys. Rev. A**107**, 033709 (2023)

**Emergence of super-Poissonian light from indistinguishable single-photon emitters**

A. Kovalenko, D. Babjak, A. Lešundák, L. Podhora, L. Lachman, P. Obšil, T. Pham, O. Číp, R. Filip, L. Slodička

Optica**10**,456-463 (2023), preprint: arXiv:2209.09059

**Optical interpretation of linear-optics superradiance and subradiance**

S. Asselie, A. Cipris, W. Guerin

Phys. Rev. A**106**, 063712 (2022),preprint: arXiv:2209.00918

**Anti-Zeno purification of spin baths by quantum probe measurements**

D. B. R. Dasari, S. Yang, A. Chakrabarti, A. Finkler, G. Kurizki, J. Wrachtrup

Nat. Comm.**13**, 7527 (2022)

**Quantum Zeno and Anti-Zeno Probes of Noise Correlations in Photon Polarization**

S. Virzì, A. Avella, F. Piacentini, M. Gramegna, T. Opatrný, A. G. Kofman, G. Kurizki, S. Gherardini, F. Caruso, I. Pietro Degiovanni, M. Genovese

Phys. Rev. Lett.**129**, 030401 (2022)

**Topological edge-states of the PT-symmetric Su-Schrieffer-Heeger model: An effective two-state description**

A. F. Tzortzakakis, A. Katsaris, N. E. Palaiodimopoulos, P. A. Kalozoumis, G. Theocharis, F. K. Diakonos, D. Petrosyan

Phys. Rev. A**106**, 023513 (2022)

**Microscopic dynamics and an effective Landau-Zener transition in quasiadiabatic preparation of spatially-ordered states of Rydberg excitations**

A. F. Tzortzakakis, D. Petrosyan, M. Fleischhauer, K. Mølmer

Phys. Rev. A**106**, 063302 (2022)

**Dissipative search of an unstructured database**

A. E. Allahverdyan, D. Petrosyan

Phys. Rev. A**105**, 032447 (2022)

**Hybrid discrete-continuous truncated Wigner approximation for driven, dissipative spin systems**

C. D. Mink, D. Petrosyan, M. Fleischhauer

Phys. Rev. Research**4**, 043136 (2022)

**Collection efficiency of optical photons generated from microwave excitations of a Bose-Einstein condensate**

A. Kurko, P. Domokos, D. Petrosyan, A. Vukics

Phys. Rev. A**105**, 053708 (2022)

**Effects of spin-exchange collisions on the fluctuation spectra of hot alkali-metal vapors**

K. Mouloudakis, G. Vasilakis, V. G. Lucivero, J. Kong, I. K. Kominis, and M. W. Mitchell

Phys. Rev. A**106**, 023112 (2022)

**Minimal quantum thermal machine in a bandgap environment: non-Markovian features and anti-Zeno advantage**

M. Xu, J. T. Stockburger, G. Kurizki, J. Ankerhold

New J. Phys.**24**, 035003 (2022)

**Single-mode quantum non-Gaussian light from warm atoms**

J. Mika, L. Lachman, T. Lamich, R. Filip, and L. Slodička

NPJ Quantum Inf.**8**, 123 (2022), preprint: arXiv:2201.05366

**Generating long-lived entangled states with free-space collective spontaneous emission**

A. C. Santos, A. Cidrim, C. J. Villas-Boas, R. Kaiser, R. Bachelard

Phys. Rev. A**105**, 053715 (2022), preprint: arXiv:2110.15033

**Quantum non-Markovianity elusive to interventions**

D. Burgarth, P. Facchi, D. Lonigro, K. Modi

Phys. Rev. A**104**, L050404 (2021), preprint: arXiv:2108.05750

**Photon-emitter dressed states in a closed waveguide**

D. Lonigro, P. Facchi, A.D. Greentree, S. Pascazio, F.V. Pepe, D. Pomarico

Phys. Rev. A**104**, 053702 (2021), preprint: arXiv:2103.10926

**Stationary excitation waves and multimerization in arrays of quantum emitters**

D. Lonigro, P. Facchi, S. Pascazio, F.V. Pepe, D. Pomarico

New J. Phys.**23**, 103033 (2021), preprint: arXiv:2106.08213

**A nanosecond-resolved atomic hydrogen magnetometer**

A. K. Spiliotis, M. Xygkis, K. Tazes, G. E. Katsoprinakis, D. Sofikitis, G. Vasilakis, T. P. Rakitzis

Phys. Chem. Chem. Phys.**23**, 21521 (2021), preprint: arXiv:2010.14579

**Non-Markovian noise that cannot be dynamically decoupled by periodic spin echo pulses**

D. Burgarth, P. Facchi, M. Fraas, R. Hillier

SciPost Physics**11**, 027 (2021), preprint: arXiv:1904.03627

**Subradiance in dilute atomic ensembles: Role of pairs and multiple scattering**

Y. A. Fofanov, I. M. Sokolov, R. Kaiser, W. Guerin

Phys. Rev. A**104**, 023705 (2021), preprint: arXiv:2012.10659

**Beyond the Rabi model: Light interactions with polar atomic systems in a cavity**

G. Scala, K. Słovik, P. Facchi, S. Pascazio, F.V. Pepe

Phys. Rev. A**104**, 013722 (2021), preprint: arXiv:2103.11232

**Optimal collection of radiation emitted by a trapped atomic ensemble**

Á. Kurkó, P. Domokos, A. Vukics, T. Bækkegaard, N. T. Zinner, J. Fortágh, D. Petrosyan

EPJ Quantum Technology**8**, 11 (2021).

**Photon-photon correlations from a pair of strongly coupled two-level emitters**

E. Darsheshdar, M. Hugbart, R. Bachelard, C. J. Villas-Boas

Phys. Rev. A**103**, 053702 (2021), preprint: arXiv:2012.03735

**van der Waals dephasing for Dicke subradiance in cold atomic clouds**

A. Cipris, R. Bachelard, R. Kaiser, W. Guerin

Phys. Rev. A**103**, 033714 (2021), preprint: arXiv:2012.06248

**Eternal adiabaticity in quantum evolution**

D. Burgarth, P. Facchi, H. Nakazato, S. Pascazio, K. Yuasa

Phys. Rev. A**103**, 032214 (2021), preprint: arXiv:2011.04713

**Subradiance with saturated atoms: population enhancement of the long-lived states**

A. Cipris, N. A. Moreira, T. S. do Espirito Santo, P. Weiss, C. J. Villas-Boas, R. Kaiser, W. Guerin, R. Bachelard

Phys. Rev. Lett.**126**, 103604 (2021), preprint: arXiv:2009.05172

**Collective emission of photons from dense, dipole-dipole interacting atomic ensembles**

D. Petrosyan, K. Mølmer

Phys. Rev. A**103**, 023703 (2021), preprint: arXiv:2009.08653

**Work Generation from Thermal Noise by Quantum Phase-Sensitive Observation**

T. Opatrny, A. Misra and G. Kurizki

Phys. Rev. Lett.**127**, 040602 (2021)

**Superradiance as single scattering embedded in an effective medium**

P. Weiss, A. Cipris, R. Kaiser, I. M. Sokolov, W. Guerin

Phys. Rev. A**103**, 023702 (2021), preprint: arXiv:2011.05201

**Hidden non-Markovianity in open quantum systems**

D. Burgarth, P. Facchi, M. Ligabò, D. Lonigro

Phys. Rev. A**103**, 012203 (2021), preprint: arXiv:2009.10605

**Light interaction with extended quantum systems in dispersive media**

G. Scala, F.V. Pepe, P. Facchi, S. Pascazio, K. Słovik

New J. Physics**22**, 123047 (2020), preprint: arXiv:2007.06320

**Quantum Zeno dynamics from general quantum operations**

D. Burgarth, P. Facchi, H. Nakazato, S. Pascazio, K. Yuasa

Quantum**4**, 289 (2020), preprint: arXiv:1809.09570

**Precision Limits of Tissue Microstructure Characterization by Magnetic Resonance Imaging**

A. Zwick, D. Suter, G. Kurizki and G. A. Alvarez

Phys. Rev. Appl.**14**, 024088 (2020)

**Minimal quantum heat manager boosted by bath spectral filtering**

M. T .Naseem, A. Misra, O. E. Mustecaplioglu and G. Kurizki

Phys. Rev. Res.**2**, 033285 (2020)

**Spin-bath polarization via disentanglement**

D. D. B. Rao, A. Ghosh, D. Gelbwaser, N. Bar-Gill and G. Kurizki

New J. Phys.**22**, 083035 (2020)

**Solitons supported by intensity-dependent dispersion**

C. Y. Lin, J. H. Chang, G. Kurizki and R. K. Lee

Opt. Lett.**45**, 1471 (2020)

**Anti-Zeno quantum advantage in fast-driven heat machines**

V. Mukherjee, A. G. Kofman and G. Kurizki

Commun. Phys.**3**, 8 (2020)