We propose a large-scale quantum simulator by multiplexing optical quantum modes in the frequency domain and arbitrarily mixing them as a boson sampling optical circuit to obtain Franc Condon Factor of large molecules. By shaping 785-nm femtosecond pump laser pulses, we generate multimode squeezed states via spontaneous parametric down conversion with a type-II PPKTP. Sum frequency mixing using a type-II PPLN between the multimode squeezed states and gate pulses that are shaped to the arbitrary superposition of the multi-spectral mode functions acts as programmable quantum gating. We complete the quantum simulation by time-dependent photon number detection at the sum-frequency wavelength at 517 nm. We describe the advantage of quantum mode manipulation in the frequency domain and place a special emphasis on group velocity dispersion engineering required to achieve them.We propose a large-scale quantum simulator by multiplexing optical quantum modes in the frequency domain and arbitrarily mixing them as a boson sampling optical circuit to obtain Franc Condon Factor of large molecules. By shaping 785-nm femtosecond pump laser pulses, we generate multimode squeezed states via spontaneous parametric down conversion with a type-II PPKTP. Sum frequency mixing using a type-II PPLN between the multimode squeezed states and gate pulses that are shaped to the arbitrary superposition of the multi-spectral mode functions acts as programmable quantum gating. We complete the quantum simulation by time-dependent photon number detection at the sum-frequency wavelength at 517 nm. We describe the advantage of quantum mode manipulation in the frequency domain and place a special emphasis on group velocity dispersion engineering required to achieve them.

The Review of Laser EngineeringJan 1, 20200 citations

Nonlinear optics for ultrafast single-photon detection

Mario Agio, Duncan G. England, Assegid M. Flatae +2 more

Elsevier eBooksJan 1, 20233 citations

Evaluation of Femtosecond Time-bin Qubits Using Frequency Up-conversion Technique

Yuta Kochi, Sunao Kurimura, Junko Ishi‐Hayase

Time-bin qubits, in which quantum information is encoded in a single photon at different times $Δ$ t, are suitable for long-distance transmission via optical fibers. However, detection of time-bin qubits has been limited to the nanosecond range owing to the limited temporal resolution of single-photon detectors. In this study, we developed an up-conversion single-photon detector (UCSPD), using commercial nonlinear crystals of different lengths. By changing the crystal length and pump power, we quantitatively evaluated the efficiency and temporal resolution of the UCSPD and determined the optimal conditions for measuring femtosecond time-bin qubits. This detector achieved a temporal resolution of 415 fs and up-conversion efficiency of 10.1 %. Consequently, we successfully evaluated single-photon level pseudo femtosecond time-bin qubits with a pulse interval of only 800 fs.Time-bin qubits, in which quantum information is encoded in a single photon at different times $Δ$t, are suitable for long-distance transmission via optical fibers. However, detection of time-bin qubits has been limited to the nanosecond range owing to the limited temporal resolution of single-photon detectors. In this study, we developed an up-conversion single-photon detector (UCSPD), using commercial nonlinear crystals of different lengths. By changing the crystal length and pump power, we quantitatively evaluated the efficiency and temporal resolution of the UCSPD and determined the optimal conditions for measuring femtosecond time-bin qubits. This detector achieved a temporal resolution of 415 fs and up-conversion efficiency of 10.1 %. Consequently, we successfully evaluated single-photon level pseudo femtosecond time-bin qubits with a pulse interval of only 800 fs.

arXiv:2205.06957May 14, 20222 citations

Ultrafast detection of single-photon level femtosecond photon echoes from coherently controlled quantum dots (要旨)

Yuta Kochi, 優太河内

Jan 1, 20250 citations

High-efficiency frequency conversion in the single-photon regime

Alex S. Clark, Shayan Shahnia, Matthew J. Collins +2 more

In this Letter we demonstrate frequency conversion in the single-photon regime through Bragg-scattering four-wave mixing with near-unit efficiency in a 750 m long commercially available dispersion-engineered highly nonlinear fiber, where all photons and pump laser frequencies are in the low-loss telecommunications band. We achieve 99.1%±4.9% downconversion and 98.0%±5.0% upconversion of photons by 12 nm using a weak coherent state with an average input of 0.27 photons per detection gate window.In this Letter we demonstrate frequency conversion in the single-photon regime through Bragg-scattering four-wave mixing with near-unit efficiency in a 750 m long commercially available dispersion-engineered highly nonlinear fiber, where all photons and pump laser frequencies are in the low-loss telecommunications band. We achieve 99.1%±4.9% downconversion and 98.0%±5.0% upconversion of photons by 12 nm using a weak coherent state with an average input of 0.27 photons per detection gate window.

Optics LettersMar 11, 201366 citations

Time-bin qubits, in which quantum information is encoded in a single photon at different times

Δ

t, are suitable for long-distance transmission via optical fibers. However, detection of time-bin qubits has been limited to the nanosecond range owing to the limited temporal resolution of single-photon detectors. In this study, we developed an up-conversion single-photon detector (UCSPD), using commercial nonlinear crystals of different lengths. By changing the crystal length and pump power, we quantitatively evaluated the efficiency and temporal resolution of the UCSPD and determined the optimal conditions for measuring femtosecond time-bin qubits. This detector achieved a temporal resolution of 415 fs and up-conversion efficiency of 10.1 %. Consequently, we successfully evaluated single-photon level pseudo femtosecond time-bin qubits with a pulse interval of only 800 fs.