APL QuantumPub Date : 2024-07-26DOI: 10.1063/5.0205848
Luis Garcia-Perez, Juan Grau-Climent, J. C. Losada, Ramón Alonso-Sanz
{"title":"A quantum Stackelberg common-pool resource game","authors":"Luis Garcia-Perez, Juan Grau-Climent, J. C. Losada, Ramón Alonso-Sanz","doi":"10.1063/5.0205848","DOIUrl":"https://doi.org/10.1063/5.0205848","url":null,"abstract":"A sequential common-pool resource game with variable elastic marginal profit is studied in this work both analytically and through numerical simulation. The game is studied in both classic and quantum approaches considering symmetric and asymmetric costs. In the classic approach, it is shown how the increase in the level of inelasticity in the model boosts the leader advantage in the perfect equilibrium solution as well as contributes to the depletion of the resource. The quantum approach enables the emergence of the symmetric Pareto optimal solution when the entanglement increases. Furthermore, for high values of the factor of entanglement, the Pareto solution is reached regardless of the level of elasticity of the game. These results are applicable to the model with symmetric and asymmetric costs.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":"24 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141800585","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}
APL QuantumPub Date : 2024-07-11DOI: 10.1063/5.0207712
Anthony C. Leung, W. Y. S. Lau, Aaron D. Tranter, Karun V. Paul, M. Rambach, Ben C. Buchler, P. K. Lam, Andrew G. White, T. Weinhold
{"title":"Highly efficient storage of cavity SPDC single photons in room temperature gradient echo memory","authors":"Anthony C. Leung, W. Y. S. Lau, Aaron D. Tranter, Karun V. Paul, M. Rambach, Ben C. Buchler, P. K. Lam, Andrew G. White, T. Weinhold","doi":"10.1063/5.0207712","DOIUrl":"https://doi.org/10.1063/5.0207712","url":null,"abstract":"Efficient quantum memories will be an essential building block of large-scale networked quantum systems and provide a link between flying photonic qubits and atomic or quasi-atomic local quantum processors. Memory efficiencies above 50% are required to be operating above the quantum no-cloning limit. High efficiency operation necessitates tailored photon source and memory pairs with matched bandwidths. In this paper, we explore the combination of an ultralow spectral bandwidth source of single photons from cavity-enhanced spontaneous parametric down-conversion with a hot gas-ensemble atomic memory. Our rubidium vapor gradient echo memory achieves 84% ± 3% recall efficiency of single photons: a record for single photon storage in a warm vapor platform that avoids bulky and complex systems, such as high vacuum and low temperature cryogenics.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":"52 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658384","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}
APL QuantumPub Date : 2024-07-11DOI: 10.1063/5.0208110
Farzad Faramarzi, Ryan Stephenson, S. Sypkens, B. Eom, Henry G. Leduc, Peter Day
{"title":"A 4–8 GHz kinetic inductance traveling-wave parametric amplifier using four-wave mixing with near quantum-limited noise performance","authors":"Farzad Faramarzi, Ryan Stephenson, S. Sypkens, B. Eom, Henry G. Leduc, Peter Day","doi":"10.1063/5.0208110","DOIUrl":"https://doi.org/10.1063/5.0208110","url":null,"abstract":"Kinetic inductance traveling-wave parametric amplifiers (KI-TWPAs) have a wide instantaneous bandwidth with a near quantum-limited noise performance and a relatively high dynamic range. Because of this, they are suitable readout devices for cryogenic detectors and superconducting qubits and have a variety of applications in quantum sensing. This work discusses the design, fabrication, and performance of a KI-TWPA based on four-wave mixing in a NbTiN microstrip transmission line. This device amplifies a signal band from 4 to 8 GHz without contamination from image tones, which are produced in a separate higher frequency band. The 4–8 GHz band is commonly used to read out cryogenic detectors, such as microwave kinetic inductance detectors and Josephson junction-based qubits. We report a measured maximum gain of over 20 dB using four-wave mixing with a 1 dB gain compression point of −58 dBm at 15 dB of gain over that band. The bandwidth and peak gain are tunable by adjusting the pump-tone frequency and power. Using a Y-factor method, we measure an amplifier-added noise of 0.5 ≤ Nadded ≤ 1.5 photons from 4.5 to 8 GHz.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":"73 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658371","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}
APL QuantumPub Date : 2024-07-11DOI: 10.1063/5.0199647
Alexander Senichev, Zachariah Martin, Yongqiang Wang, Owen M. Matthiessen, A. Lagutchev, Han Htoon, A. Boltasseva, V. Shalaev
{"title":"Quantum emitters in aluminum nitride induced by heavy ion irradiation","authors":"Alexander Senichev, Zachariah Martin, Yongqiang Wang, Owen M. Matthiessen, A. Lagutchev, Han Htoon, A. Boltasseva, V. Shalaev","doi":"10.1063/5.0199647","DOIUrl":"https://doi.org/10.1063/5.0199647","url":null,"abstract":"The integration of solid-state single-photon sources with foundry-compatible photonic platforms is crucial for practical and scalable quantum photonic applications. This study explores aluminum nitride (AlN) as a material with properties highly suitable for integrated on-chip photonics and the ability to host defect-center related single-photon emitters. We have conducted a comprehensive analysis of the creation of single-photon emitters in AlN, utilizing heavy ion irradiation and thermal annealing techniques. Subsequently, we have performed a detailed analysis of their photophysical properties. Guided by theoretical predictions, we assessed the potential of Zirconium (Zr) ions to create optically addressable spin defects and employed Krypton (Kr) ions as an alternative to target lattice defects without inducing chemical doping effects. With a 532 nm excitation wavelength, we found that single-photon emitters induced by ion irradiation were primarily associated with vacancy-type defects in the AlN lattice for both Zr and Kr ions. The density of these emitters increased with ion fluence, and there was an optimal value that resulted in a high density of emitters with low AlN background fluorescence. Under a shorter excitation wavelength of 405 nm, Zr-irradiated AlN exhibited isolated point-like emitters with fluorescence in the spectral range theoretically predicted for spin-defects. However, similar defects emitting in the same spectral range were also observed in AlN irradiated with Kr ions as well as in as-grown AlN with intrinsic defects. This result is supportive of the earlier theoretical predictions, but at the same time highlights the difficulties in identifying the sought-after quantum emitters with interesting properties related to the incorporation of Zr ions into the AlN lattice by fluorescence alone. The results of this study largely contribute to the field of creating quantum emitters in AlN by ion irradiation and direct future studies emphasizing the need for spatially localized Zr implantation and testing for specific spin properties.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":"49 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141658519","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}
APL QuantumPub Date : 2024-05-20DOI: 10.1063/5.0205444
Yao Yao, Daniel F. Fernandes, T. Košutová, Tomas Kubart, Zhen Zhang, François Lefloch, Frédéric Gustavo, Axel Leblanc, J. Lábár, B. Pécz, Shi-Li Zhang
{"title":"Self-aligned formation of superconducting sub-5 nm PtSi films","authors":"Yao Yao, Daniel F. Fernandes, T. Košutová, Tomas Kubart, Zhen Zhang, François Lefloch, Frédéric Gustavo, Axel Leblanc, J. Lábár, B. Pécz, Shi-Li Zhang","doi":"10.1063/5.0205444","DOIUrl":"https://doi.org/10.1063/5.0205444","url":null,"abstract":"Platinum silicide (PtSi) presents a promising superconductor for achieving silicon-based Josephson field-effect transistors (JoFETs). In a viable process flow to realize self-aligned PtSi formation, thermal oxidation at 600 °C is required to form a protective oxide layer on the surface of the as-formed PtSi selectively against Pt to facilitate subsequent selective etch in aqua regia. However, sub-10 nm PtSi films tend to agglomerate and even break into discrete PtSi islands upon thermal treatments above 500 °C. To achieve nanoscale JoFETs, we have developed a simple alternative with chemical oxidation at room temperature leading to the formation of homogeneous sub-5 nm PtSi films. The critical temperature of the resultant superconducting PtSi films is found to increase from 0.66 to 0.90 K when the PtSi thickness is raised from 3.1 to 12.7 nm, while, concurrently, the PtSi grains grow larger in thicker films. The critical temperature also increases from 0.53 to 0.66 K for the 3.1 nm PtSi film when the formation temperature is raised from 400 to 500 °C.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":"59 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141123307","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}
APL QuantumPub Date : 2024-05-17DOI: 10.1063/5.0185239
A. E. Rastegin
{"title":"Entropic uncertainty relations for measurements assigned to a projective two-design","authors":"A. E. Rastegin","doi":"10.1063/5.0185239","DOIUrl":"https://doi.org/10.1063/5.0185239","url":null,"abstract":"The current study aims to examine uncertainty relations for quantum measurements assigned to a projective two-design. Complete sets of mutually unbiased bases and symmetric informationally complete measurements are important cases of such measurements. To characterize the amount of uncertainty, we use the Tsallis and Rényi entropies as well as the probabilities of separate outcomes. The obtained results are based on an estimation of the index of coincidence. They improve some uncertainty relations given in the literature.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":"6 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140963342","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}
APL QuantumPub Date : 2024-05-13DOI: 10.1063/5.0198344
Bharat S. Rawal, Peter J. Curry
{"title":"Challenges and opportunities on the horizon of post-quantum cryptography","authors":"Bharat S. Rawal, Peter J. Curry","doi":"10.1063/5.0198344","DOIUrl":"https://doi.org/10.1063/5.0198344","url":null,"abstract":"Large quantum computers have the potential to break many cryptographic systems, e.g., Rivest–Shamir–Adleman, Diffie–Hellman key exchange, and the elliptical curve cryptosystem. The Department of Defense (DoD) is aware of this threat, and the National Institute of Standards and Technology is preparing a set of approved encryption and signature schemes that are not susceptible to these attacks by quantum computers, the so-called Post-Quantum Cryptography (PQC). The task of substituting older encryption and signature schemes raises a number of questions, to which there are not yet clear answers. In this research, we investigate the transition to PQC on existing networks, explain the approved PQC schemes, describe the likely path to an adaptation of PQC, and offer forward guidance on challenges and threats that may be encountered in the process of transition to PQC. This paper discusses the impacts of the new PQC schemes on network performance and speculates on possible side-channel attacks on the new encryption scheme. This paper offers hardware/software solutions based on the Split-protocol.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":"9 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140985259","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}
APL QuantumPub Date : 2024-05-08DOI: 10.1063/5.0197119
Harry C. P. Kendell, Giacomo Ferranti, Carrie A. Weidner
{"title":"Deterministic generation of highly squeezed GKP states in ultracold atoms","authors":"Harry C. P. Kendell, Giacomo Ferranti, Carrie A. Weidner","doi":"10.1063/5.0197119","DOIUrl":"https://doi.org/10.1063/5.0197119","url":null,"abstract":"We demonstrate a method for encoding Gottesman–Kitaev–Preskill (GKP) error-correcting qubits with single ultracold atoms trapped in individual sites of a deep optical lattice. Using quantum optimal control protocols, we demonstrate the generation of GKP qubit states with 10 dB squeezing, which is the current minimum allowable squeezing level for use in surface code error correction. States are encoded in the vibrational levels of the individual lattice sites and generated via phase modulation of the lattice potential. Finally, we provide a feasible experimental protocol for the realization of these states. Our protocol opens up possibilities for generating large arrays of atomic GKP states for continuous-variable quantum information.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":" 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141000691","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}
APL QuantumPub Date : 2024-05-07DOI: 10.1063/5.0190798
D. Marchant, I. Faruque, J. Barreto
{"title":"Generating quantum correlated photon pairs in a hybrid silicon–BTO platform","authors":"D. Marchant, I. Faruque, J. Barreto","doi":"10.1063/5.0190798","DOIUrl":"https://doi.org/10.1063/5.0190798","url":null,"abstract":"Here, we show photon pair generation from ring resonator and waveguide structures in a hybrid silicon–BTO on an insulator platform with a pulsed pump. Our analysis of single photon and coincidence generation rates show that spontaneous four-wave mixing is comparable to that expected from SOI devices with similar characteristics and find γeff of (14.7 ± 1.3) and (2.0 ± 0.3) MHz/mW2 for ring resonator and waveguide structures, respectively.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":"27 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141005336","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}
APL QuantumPub Date : 2024-04-15DOI: 10.1063/5.0191416
S. Ding, Shiyuan Zhao, Heming Huang, F. Grillot
{"title":"Observation of amplitude squeezing in a constant-current-driven distributed feedback quantum dot laser with optical feedback","authors":"S. Ding, Shiyuan Zhao, Heming Huang, F. Grillot","doi":"10.1063/5.0191416","DOIUrl":"https://doi.org/10.1063/5.0191416","url":null,"abstract":"We illustrate the generation of single-mode amplitude squeezing in a distributed feedback quantum dot laser driven by a constant-current pump. Achieving broadband amplitude squeezing of 1.7 dB over a 10 GHz range at room temperature is realized by suppressing carrier noise and implementing optical feedback. The noise-corrected squeezing level reached 5.1 dB. Furthermore, the examination of the zero-delay second-order correlation function demonstrates the robust feedback stability of the amplitude-squeezed state in the quantum dot laser compared to a reference quantum well laser. This investigation lays the groundwork for future advancements in integrated optical quantum chips.","PeriodicalId":517678,"journal":{"name":"APL Quantum","volume":"52 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140699374","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}