April 2025
·
6 Reads
Optics Communications
This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.
April 2025
·
6 Reads
Optics Communications
July 2024
·
50 Reads
·
3 Citations
We demonstrate the optical response from high-Tc superconductor nanowires at temperatures above that of liquid nitrogen. Using hard oxide A l 2 O 3 as a mask material, we achieved miniaturized YB a 2 C u 3 O 7 − δ wires with widths nearing 100 nm, a significant milestone for highly sensitive photodetectors. We investigated the photoresponse of these nanowires at temperatures almost an order of magnitude higher than previously reported, under varying temperature and bias current conditions. Our findings reveal a strong correlation between the optical response and the critical parameters of the superconductor, with peak optical responses close to the critical values of temperature and bias current density. Nanowire response to wavelengths from visible to near-infrared range demonstrated a pronounced absorption maximum at temperatures below Tc. These results lay a solid foundation for the development of high-Tc superconductor nanowire single-photon detectors, understanding of nanoscale high-Tc superconductor structure optical behavior, and advancing the prospects of quantum technologies.
June 2024
·
40 Reads
Light Science & Applications
Superconductor-semiconductor hybrid devices can bridge the gap between solid-state-based and photonics-based quantum systems, enabling new hybrid computing schemes, offering increased scalability and robustness. One example for a hybrid device is the superconducting light-emitting diode (SLED). SLEDs have been theoretically shown to emit polarization-entangled photon pairs by utilizing radiative recombination of Cooper pairs. However, the two-photon nature of the emission has not been shown experimentally before. We demonstrate two-photon emission in a GaAs/AlGaAs SLED. Measured electroluminescence spectra reveal unique two-photon superconducting features below the critical temperature ( T c ), while temperature-dependent photon-pair correlation experiments ( g ⁽²⁾ ( τ , T )) demonstrate temperature-dependent time coincidences below T c between photons emitted from the SLED. Our results pave the way for compact and efficient superconducting quantum light sources and open new directions in light-matter interaction studies.
January 2024
·
3 Reads
We report the first observation of the ac Stark modulation of the energy an exciton-polariton condensate by differential reflectivity measurement and coherent oscillations. Our results enable new quantum technologies and fundamental condensed matter research.
January 2024
·
1 Read
We experimentally demonstrated two-photon emission in GaAs/AlGaAs superconducting light emitting diodes (SLEDs), observing EL spectra and g ⁽²⁾ photon correlations corresponding to Cooper-pair recombination. We utilized a superlattice structure and transparent superconducting contacts to enhance pair emission.
June 2023
·
7 Reads
June 2023
June 2023
·
11 Reads
May 2023
·
66 Reads
·
8 Citations
We report ultrafast optical response in high-Tc superconductor (YBa2Cu3O7−δ) based microwires operating at 76 K and we find a rise time ∼850 ps and a fall time ∼1250 ps and an upper limit of timing jitter of ∼100 ps, using twice the standard deviation of the fitted data. In our experiment, incident power is proven to be an important factor for a device jitter. At low incident power, a lower rate of hot-spot generation by a smaller number of absorbed photons results in a longer latency time to obtain the required number of hot-spots for superconductor-to-normal transition. The lower hot-spot generation rate also results in larger timing jitter of the device. Whereas, at high incident power, a higher hot-spot generation rate yields shorter latency and smaller timing jitter. These observations agree well with our statistical model. Enhancing the sensitivity of the current device can enable future high-Tc superconductor nanowire single photon detectors, toward the widespread use of ultrafast quantum technologies.
April 2023
·
12 Reads
·
1 Citation
We propose a compact and highly efficient scheme for solid-state photonic quantum gates. At the core of our scheme is a SWAPϕ gate based on giant Cooper-pair-based optical nonlinearity we predict in a semiconductor-superconductor structure, selectively introducing a phase to the |Ψ+〉 Bell state. We theoretically demonstrate this scheme on a practical device based on a superconducting contact coupled to a GaAs/AlGaAs waveguide structure. We model the Cooper-pair-induced nonlinear change of the refractive index showing strong nonlinearities at energies close to the superconducting gap inside a semiconductor band. We calculate the fidelity of the proposed SWAPϕ gate, as well as the sensitivity of the gate to device parameters. As short photon wave packets are crucial for efficient higher-order interactions, we investigate the integrated fidelity for short wave packets with different central wavelengths and bandwidths, providing limiting factors as well as possible optimizations. This theoretically demonstrated concept can pave the way toward practical realizations of scalable photonic quantum circuits.
... [19] The Lombardi team utilized optimized IBE technology combined with a hard mask to fabricate 65 nm wide nanowires on a 10 nm-thick YBCO film and measured dark pulses at 9.3 K. [14,16] Amari et al. employed ion irradiation technology to prepare 30 nm-thick, 126 nm wide YBCO nanowires, followed by encapsulation for protection. [26] Additionally, some novel nanowire patterning methods have emerged, such as using alumina templates, [27,28] SrTiO 3 insulating film templates, [29,30] AFM contact lithography, [31] and superlattice nanowire pattern transfer (SNAP). [32] For example, Kumar et al. used Al 2 O 3 as a mask to fabricate YBCO nanowires with a width close to 100 nm, achieving an optical response above the liquid nitrogen temperature (81 K), but the film thickness was 50 nm. ...
July 2024
... Therefore, the careful choice of the material is crucial. In particular, recent experiments show that HTS exhibits low jitter times and ultra-fast response times on the order of 100 ps, [17][18][19][20] while LTS nanowires typically show three orders higher response times (about 10-40 ns). The general physics of SNSPD is typically modeled by tracking the quasi-particle generation from the photon incidence or, equivalently, by calculating the temperature evolution and its effect on superconducting properties. ...
May 2023
... It was shown theoretically 28 that a spin-singlet Cooper pair may recombine with a pair of holes, resulting in a polarization-entangled photon pair in the |Ψ þ 〉 Bell state. This concept has been shown to be also at the core of Cooper-pair based twophoton amplification in waveguides 29 , Bell-state analyzers 30 and nonlinear photonic universal quantum gates 31 . While the nearly deterministic on-demand sources such as single atoms or quantum dots (QD) offer certain advantages [32][33][34] , the most widely used source of entangled photons in quantum information processing (QIP) is parametric down conversion (PDC) 5,[35][36][37][38][39][40][41][42][43] , which has a probabilistic naturevery similar to the SLED source. ...
April 2023
... Exciton-polaritons [1], half-light half-matter quasiparticles, arise from the strong coupling regime between an excitonic and a photonic state when the coupling rate between the two states is faster than the respective dissipation rates. Exciton-polaritons have been demonstrated in many nanofabricated photonic strutures such as microcavities [1][2][3], photonic crystals waveguides [4][5][6][7][8][9][10][11][12][13][14][15] or micropillar lattices [16][17][18]. From their hybrid nature, the exciton-polaritons hold the properties of their light and matter counterparts, and therefore are nonlinear bosons that can ballistically propagate. ...
December 2022
... Quantum tunneling at metallic surfaces is the physical principle behind the operation of the scanning tunneling microscope [11][12][13] . It also lays a foundation for nanotechnologies, such as the tunnel diode 14 and resonant tunneling 15 , and some interdisciplinary sciences including quantum biology [16][17][18] and quantum chemistry 19,20 . As a ubiquitous behavior of microscopic matters, such as electron 21 , proton 22 , nucleon 9 , photon 23,24 , and superconducting Cooper pairs 25 , quantum tunneling has been observed in many experiments 20,[26][27][28][29][30][31] . ...
March 2022
Physical Review Letters
... More complex structures, however, cannot be formulated analytically, hence, we have previously introduced a method for finding strongly coupled structures via a near-field inverse design approach [32]. In accordance with this method, we run an evolutionary optimization based on a genetic algorithm, where the optimization function is defined as the mean intensity E m of the near-field optical response in a small spectral window around λ exc . ...
January 2020
... Notably, with unconventional pairing states, such as d-wave pairings, the dGSJ states evolve into flat zero-energy surface Andreev bound states (ZESABSs) [13][14][15][16] and can be found at normal regions of arbitrary thickness [17,18]. The ZESABSs manifest themselves as a zero bias conductance peak in tunneling spectroscopy [14,17,[19][20][21][22][23]. ...
August 2020
... Recently, Xing et al fabricated a nanostrip with 10 µm width and 100 nm thickness by PLD and selective epitaxial growth method. The J c of the nanostrip was 5.5 ×10 5 A cm −2 at 77 K and showed a photo-response above 85 K [24]. However, it is technologically challenging to fabricate a high quality cuprate nanostrip with a 5 nm thick and 100 nm wide dimensions, and the single-photon sensitivity can not be compared with Nbbased SNSPD [25]. ...
July 2020
... A similar scenario is also observed in the heterostructures of PbS QDs and plasmonic Cu 2-x Se nanocrystals [64]. Strugo et al. numerically studied the plasmon-assisted Cooper-pair-based two-photon emission in a superconducting Nb layer [317]. With an SPP mode traveling along the interface between the highly doped n-type InGaAs and Nb layers, the superconductorsemiconductor waveguiding system witnesses a 45-fold enhancement in mode confinement and the two-photon gain elevated by 3 orders of magnitude, implying a high potential in two-photon lasing. ...
March 2020
... [14] Leveraging the impact of the optical Stark effect (OSE) on these exciton-polaritons confined between two DBR mirrors becomes particularly promising, given the successful control of polaritons. [15][16][17] In recent times, researchers have explored the influence of the OSE in 2D WS2 [18] monolayers at room temperature and developed an all-optical method to realize topological insulators using OSE within exciton-polariton systems. [19] These studies provide ways to manipulate polaritons through OSE with a large degree of control freedom. ...
November 2019
ACS Photonics