We derive a general quantum exchange fluctuation theorem for multipartite systems with arbitrary coupling strengths by taking into account the informational contribution of the back-action of the quantum measurements, which contributes to the increase in the von-Neumann entropy of the quantum system. The resulting second law of thermodynamics is tighter than the conventional Clausius inequality. The derived bound is the quantum mutual information of the conditional thermal state, which is a thermal state conditioned on the initial energy measurement. These results elucidate the role of quantum correlations in the heat exchange between multiple subsystems.
{"title":"Exchange fluctuation theorems for strongly interacting quantum pumps","authors":"A. Sone, D. Soares-Pinto, Sebastian Deffner","doi":"10.1116/5.0152186","DOIUrl":"https://doi.org/10.1116/5.0152186","url":null,"abstract":"We derive a general quantum exchange fluctuation theorem for multipartite systems with arbitrary coupling strengths by taking into account the informational contribution of the back-action of the quantum measurements, which contributes to the increase in the von-Neumann entropy of the quantum system. The resulting second law of thermodynamics is tighter than the conventional Clausius inequality. The derived bound is the quantum mutual information of the conditional thermal state, which is a thermal state conditioned on the initial energy measurement. These results elucidate the role of quantum correlations in the heat exchange between multiple subsystems.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46936173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jianing Li, Kelvin Lim, Swarup Das, T. Zanon-Willette, C. Feng, Paul Robert, A. Bertoldi, P. Bouyer, C. Kwong, Shau-Yu Lan, D. Wilkowski
Transversely loaded bidimensional-magneto-optical-traps (2D-MOTs) have been recently developed as high flux sources for cold strontium atoms to realize a new generation of compact experimental setups. Here, we discuss on the implementation of a cross-polarized bi-color slower for a strontium atomic beam, improving the 2D-MOT loading and increasing the number of atoms up to [Formula: see text] atoms in the 461 nm MOT. Our slowing scheme addresses simultaneously two excited Zeeman substates of the 88Sr 1[Formula: see text]P1 transition at 461 nm. We also realized a three-axis active feedback control of the magnetic field down to the microgauss regime. Such a compensation is performed thanks to a network of eight magnetic field probes arranged in a cuboid configuration around the atomic cold sample and a pair of coils in a quasi-Helmholtz configuration along each of three Cartesian directions. Our active feedback is capable of efficiently suppressing most of the magnetically induced position fluctuations of the 689 nm intercombination-line MOT.
{"title":"Bi-color atomic beam slower and magnetic field compensation for ultracold gases","authors":"Jianing Li, Kelvin Lim, Swarup Das, T. Zanon-Willette, C. Feng, Paul Robert, A. Bertoldi, P. Bouyer, C. Kwong, Shau-Yu Lan, D. Wilkowski","doi":"10.1116/5.0126745","DOIUrl":"https://doi.org/10.1116/5.0126745","url":null,"abstract":"Transversely loaded bidimensional-magneto-optical-traps (2D-MOTs) have been recently developed as high flux sources for cold strontium atoms to realize a new generation of compact experimental setups. Here, we discuss on the implementation of a cross-polarized bi-color slower for a strontium atomic beam, improving the 2D-MOT loading and increasing the number of atoms up to [Formula: see text] atoms in the 461 nm MOT. Our slowing scheme addresses simultaneously two excited Zeeman substates of the 88Sr 1[Formula: see text]P1 transition at 461 nm. We also realized a three-axis active feedback control of the magnetic field down to the microgauss regime. Such a compensation is performed thanks to a network of eight magnetic field probes arranged in a cuboid configuration around the atomic cold sample and a pair of coils in a quasi-Helmholtz configuration along each of three Cartesian directions. Our active feedback is capable of efficiently suppressing most of the magnetically induced position fluctuations of the 689 nm intercombination-line MOT.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42242320","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We show the existence of a majorization ladder in bosonic Gaussian channels, that is, we prove that the channel output resulting from the [Formula: see text] energy eigenstate (Fock state) majorizes the channel output resulting from the [Formula: see text] energy eigenstate (Fock state). This reflects a remarkable link between the energy at the input of the channel and a disorder relation at its output as captured by majorization theory. This result was previously known in the special cases of a pure-loss channel and quantum-limited amplifier, and we achieve here its non-trivial generalization to any single-mode phase-covariant (or -contravariant) bosonic Gaussian channel. The key to our proof is the explicit construction of a column-stochastic matrix that relates the outputs of the channel for any two subsequent Fock states at its input. This is made possible by exploiting a recently found recurrence relation on multiphoton transition probabilities for Gaussian unitaries [Jabbour and Cerf, Phys. Rev. Res. 3, 043065 (2021)]. Possible generalizations and implications of these results are then discussed.
{"title":"Majorization ladder in bosonic Gaussian channels","authors":"Z. Van Herstraeten, M. Jabbour, N. Cerf","doi":"10.1116/5.0129704","DOIUrl":"https://doi.org/10.1116/5.0129704","url":null,"abstract":"We show the existence of a majorization ladder in bosonic Gaussian channels, that is, we prove that the channel output resulting from the [Formula: see text] energy eigenstate (Fock state) majorizes the channel output resulting from the [Formula: see text] energy eigenstate (Fock state). This reflects a remarkable link between the energy at the input of the channel and a disorder relation at its output as captured by majorization theory. This result was previously known in the special cases of a pure-loss channel and quantum-limited amplifier, and we achieve here its non-trivial generalization to any single-mode phase-covariant (or -contravariant) bosonic Gaussian channel. The key to our proof is the explicit construction of a column-stochastic matrix that relates the outputs of the channel for any two subsequent Fock states at its input. This is made possible by exploiting a recently found recurrence relation on multiphoton transition probabilities for Gaussian unitaries [Jabbour and Cerf, Phys. Rev. Res. 3, 043065 (2021)]. Possible generalizations and implications of these results are then discussed.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46134781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Once a distant dream, quantum networks are very much a present reality, with an exciting future.
量子网络曾经是一个遥远的梦想，但现在却是现实，有着令人兴奋的未来。
{"title":"Progress in quantum networks","authors":"A. Forbes","doi":"10.1116/5.0118569","DOIUrl":"https://doi.org/10.1116/5.0118569","url":null,"abstract":"Once a distant dream, quantum networks are very much a present reality, with an exciting future.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48524668","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Hong–Ou–Mandel (HOM) effect is a fascinating quantum phenomenon that defies classical explanation. Traditionally, remote nonlinear sources have been used to achieve coincident photons at the HOM beam splitter. Here, we suggest that the coincident emission source required for HOM interference can be created locally using superradiant near field coupled emitters positioned across the beam splitter gap. We show that sensitivity to permittivity changes in the beam splitter gap, and corresponding Fisher information can be substantially enhanced with HOM photon detection. Subsequently, we outline several strategies for integration of superradiant emitters with practical sensor systems. Taken together, these findings should pave a way for a wide array of near field HOM quantum sensors and novel quantum devices.
{"title":"Hong–Ou–Mandel sensing via superradiant coupling of discrete fluorescent emitters","authors":"R. Shugayev, P. Lu, Yuhua Duan, M. Buric","doi":"10.1116/5.0091206","DOIUrl":"https://doi.org/10.1116/5.0091206","url":null,"abstract":"The Hong–Ou–Mandel (HOM) effect is a fascinating quantum phenomenon that defies classical explanation. Traditionally, remote nonlinear sources have been used to achieve coincident photons at the HOM beam splitter. Here, we suggest that the coincident emission source required for HOM interference can be created locally using superradiant near field coupled emitters positioned across the beam splitter gap. We show that sensitivity to permittivity changes in the beam splitter gap, and corresponding Fisher information can be substantially enhanced with HOM photon detection. Subsequently, we outline several strategies for integration of superradiant emitters with practical sensor systems. Taken together, these findings should pave a way for a wide array of near field HOM quantum sensors and novel quantum devices.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42502652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
An important prerequisite for quantum communication networks is the transfer and manipulation of single particles on a chip as well as their interconversion to single photons for long-range information exchange. GHz acoustic waves are versatile tools for the implementation of these functionalities in hybrid quantum systems. In particular, flying excitons propelled by GHz surface acoustic waves (SAWs) can potentially satisfy this prerequisite. In this article, we review recent works on the application of GHz SAWs to realize flying excitons in semiconductor-based systems. Most importantly, we have identified suitable two-level centers for the storage of single excitons, thus forming single excitonic qubits, and interconverted them to single photons with a very high emission rate dictated by the GHz-SAW pumping. The work covered here paves the way for on-chip, exciton-based qubit manipulation.
{"title":"Manipulation of flying and single excitons by GHz surface acoustic waves","authors":"M. Yuan, K. Biermann, P. Santos","doi":"10.1116/5.0095152","DOIUrl":"https://doi.org/10.1116/5.0095152","url":null,"abstract":"An important prerequisite for quantum communication networks is the transfer and manipulation of single particles on a chip as well as their interconversion to single photons for long-range information exchange. GHz acoustic waves are versatile tools for the implementation of these functionalities in hybrid quantum systems. In particular, flying excitons propelled by GHz surface acoustic waves (SAWs) can potentially satisfy this prerequisite. In this article, we review recent works on the application of GHz SAWs to realize flying excitons in semiconductor-based systems. Most importantly, we have identified suitable two-level centers for the storage of single excitons, thus forming single excitonic qubits, and interconverted them to single photons with a very high emission rate dictated by the GHz-SAW pumping. The work covered here paves the way for on-chip, exciton-based qubit manipulation.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45931040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The field of quantum communication is thriving as a complement to conventional telecommunication with its distinctive feature of absolute security. As the core technology for delivering quantum information, substantial advances in quantum communication have already been demonstrated on various platforms, including photonic systems. Among all of them, the orbital angular momentum (OAM) of photons with its infinite Hilbert space has attracted much attention and has been widely employed in both classical and quantum regimes. In particular, many types of fiber have been designed and fabricated to allow transmitting OAM of photons. Here, we review recent progress in transmitting OAM quantum states through different types of fiber, including few-mode fibers, multi-mode fibers, ring-core fibers, and single-mode fibers. We also discuss the challenges and prospects of quantum OAM in fibers.
{"title":"Quantum orbital angular momentum in fibers: A review","authors":"Jian Wang, Qianke Wang, Jun Liu, Dawei Lyu","doi":"10.1116/5.0101179","DOIUrl":"https://doi.org/10.1116/5.0101179","url":null,"abstract":"The field of quantum communication is thriving as a complement to conventional telecommunication with its distinctive feature of absolute security. As the core technology for delivering quantum information, substantial advances in quantum communication have already been demonstrated on various platforms, including photonic systems. Among all of them, the orbital angular momentum (OAM) of photons with its infinite Hilbert space has attracted much attention and has been widely employed in both classical and quantum regimes. In particular, many types of fiber have been designed and fabricated to allow transmitting OAM of photons. Here, we review recent progress in transmitting OAM quantum states through different types of fiber, including few-mode fibers, multi-mode fibers, ring-core fibers, and single-mode fibers. We also discuss the challenges and prospects of quantum OAM in fibers.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48451065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In order to develop a method for evaluating vibrational energies and wave functions of a polyatomic molecule by quantum computing, we introduce the reduced multistate contracted variational quantum eigensolver (RMC-VQE) method, which is a variant of the multistate contracted VQE method [Parrish et al., Phys. Rev. Lett. 122, 230401 (2019)], and apply the RMC-VQE method to a two-mode model of CO2. In the RMC-VQE method, much fewer matrix elements of the Hamiltonian are evaluated on the quantum computer than in the MC-VQE method. By measuring the matrix elements of the Hamiltonian using the quantum computer ibm_kawasaki and diagonalizing the Hamiltonian matrix on a classical computer, we obtain the vibrational energies of the Fermi doublet, which differ from the exact energies obtained using a classical computer by less than 0.1 cm−1. We also obtain accurate vibrational wave functions of the Fermi doublet states.
{"title":"Evaluation of vibrational energies and wave functions of CO2 on a quantum computer","authors":"E. Lötstedt, K. Yamanouchi, Yutaka Tachikawa","doi":"10.1116/5.0091144","DOIUrl":"https://doi.org/10.1116/5.0091144","url":null,"abstract":"In order to develop a method for evaluating vibrational energies and wave functions of a polyatomic molecule by quantum computing, we introduce the reduced multistate contracted variational quantum eigensolver (RMC-VQE) method, which is a variant of the multistate contracted VQE method [Parrish et al., Phys. Rev. Lett. 122, 230401 (2019)], and apply the RMC-VQE method to a two-mode model of CO2. In the RMC-VQE method, much fewer matrix elements of the Hamiltonian are evaluated on the quantum computer than in the MC-VQE method. By measuring the matrix elements of the Hamiltonian using the quantum computer ibm_kawasaki and diagonalizing the Hamiltonian matrix on a classical computer, we obtain the vibrational energies of the Fermi doublet, which differ from the exact energies obtained using a classical computer by less than 0.1 cm−1. We also obtain accurate vibrational wave functions of the Fermi doublet states.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48320195","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Holloway, N. Prajapati, J. Sherman, A. Rüfenacht, A. Artusio-Glimpse, M. Simons, Amy K. Robinson, D. L. La Mantia, E. Norrgard
We investigate the Stark shift in Rydberg rubidium atoms through electromagnetically induced transparency for the measurement of direct current (dc) and 60 Hz alternating current (ac) voltages. This technique has direct application to the calibration of voltage measurement instrumentation. We present experimental results for different atomic states that allow for dc and ac voltage measurements ranging from 0 to 12 V. While the state-of-the-art method for realizing the volt, the Josephson voltage standard, is significantly more accurate, the Rydberg atom-based method presented here has the potential to be a calibration standard with more favorable size, weight, power, and cost. We discuss the steps necessary to develop the Rydberg atom-based voltage measurement as a complementary method for dissemination of the voltage scale directly to the end user and discuss sources of uncertainties for these types of experiments.
{"title":"Electromagnetically induced transparency based Rydberg-atom sensor for traceable voltage measurements","authors":"C. Holloway, N. Prajapati, J. Sherman, A. Rüfenacht, A. Artusio-Glimpse, M. Simons, Amy K. Robinson, D. L. La Mantia, E. Norrgard","doi":"10.1116/5.0097746","DOIUrl":"https://doi.org/10.1116/5.0097746","url":null,"abstract":"We investigate the Stark shift in Rydberg rubidium atoms through electromagnetically induced transparency for the measurement of direct current (dc) and 60 Hz alternating current (ac) voltages. This technique has direct application to the calibration of voltage measurement instrumentation. We present experimental results for different atomic states that allow for dc and ac voltage measurements ranging from 0 to 12 V. While the state-of-the-art method for realizing the volt, the Josephson voltage standard, is significantly more accurate, the Rydberg atom-based method presented here has the potential to be a calibration standard with more favorable size, weight, power, and cost. We discuss the steps necessary to develop the Rydberg atom-based voltage measurement as a complementary method for dissemination of the voltage scale directly to the end user and discuss sources of uncertainties for these types of experiments.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45242532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We study the long-time decay of rotating turbulence in Bose–Einstein condensates (BECs). We consider the Gross–Pitaevskii equation in a rotating frame of reference and review different formulations for the Hamiltonian of a rotating BEC. We discuss how the energy can be decomposed and present a method to generate out-of-equilibrium initial conditions. We also present a method to generate finite-temperature states of rotating BECs compatible with the Canonical or the Grand canonical ensembles. Finally, we integrate numerically rotating BECs in cigar-shaped traps. A transition is found in the system dynamics as the rotation rate is increased, with a final state of the decay of the turbulent flow compatible with an Abrikosov lattice in a finite-temperature thermalized state.
{"title":"Thermalized Abrikosov lattices from decaying turbulence in rotating BECs","authors":"Julian Amette Estrada, M. Brachet, P. Mininni","doi":"10.1116/5.0123277","DOIUrl":"https://doi.org/10.1116/5.0123277","url":null,"abstract":"We study the long-time decay of rotating turbulence in Bose–Einstein condensates (BECs). We consider the Gross–Pitaevskii equation in a rotating frame of reference and review different formulations for the Hamiltonian of a rotating BEC. We discuss how the energy can be decomposed and present a method to generate out-of-equilibrium initial conditions. We also present a method to generate finite-temperature states of rotating BECs compatible with the Canonical or the Grand canonical ensembles. Finally, we integrate numerically rotating BECs in cigar-shaped traps. A transition is found in the system dynamics as the rotation rate is increased, with a final state of the decay of the turbulent flow compatible with an Abrikosov lattice in a finite-temperature thermalized state.","PeriodicalId":93525,"journal":{"name":"AVS quantum science","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41517536","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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