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C. Hnatovsky

Publications and source records attributed to C. Hnatovsky.

3 recordsLinked to original sources

Radiowave-induced Resistance Oscillations

Microwave-induced resistance oscillations (MIROs) occur when a 2D electron gas is subjected to radiation of frequency $\omega = 2 \pi f$ and varying magnetic field $B$. MIROs are periodic in $1/B$, with the period determined by the radiation frequency $\omega$, and their amplitude scales with the radiation power. Stepping from single-photon transitions between Landau levels, MIROs are found on the low-field side of the cyclotron resonance, $\omega_c \lesssim \omega$, where $\omega_c$ is the cyclotron frequency. Here, we report on another class of magneto resistance oscillations, which are induced by high-intensity radiation in the radio frequency range and occur at $\omega_c \gg \omega$. These oscillations are independent of frequency $\omega$, can be either $1/B$ or $1/B^2$-periodic, and their period is controlled by the radiation electric field. We further show that using a displacement model in the limit of short-range (``sharp'') disorder we can extract the radiation field and the width of the cyclotron resonance.

cond-mat.mes-hall

Storage of telecom wavelength heralded single photons in a fiber cavity quantum memory

We demonstrate the storage and retrieval of heralded single photons in a fiber-based cavity quantum memory. The photons are stored, and retrieved, from the memory using quantum frequency conversion which switches the photon into, and out of, resonance with the cavity. The photons, generated in the telecom O-band with a bandwidth of 81\,GHz, are retrieved from the memory with a $1/e$ lifetime of 1.64$\mu$s, or 32.8 cavity round trips. We show that non-classical photon statistics remain for 70 round trips. The internal memory efficiency after 0.5$\mu$s of storage is $10.9 \pm 0.5$%; a coupling efficiency of 60% into the memory cavity yields a total efficiency of $6.0\pm0.3$%. These results mark a crucial step forward in the development of fiber-based quantum memories, and high-bandwidth memories operating at telecom wavelengths, with applications to photon source multiplexing and fiber-based quantum networking.

quant-ph

A fiber-integrated quantum memory for telecom light

We demonstrate the storage and on-demand retrieval of single-photon-level telecom pulses in a fiber cavity. The cavity is formed by fiber Bragg gratings at either end of a single-mode fiber. Photons are mapped into, and out of, the cavity using quantum frequency conversion driven by intense control pulses. In a first, spliced-fiber, cavity we demonstrate storage up to 0.55$\mu$s (11 cavity round trips), with $11.3 \pm 0.1$% total memory efficiency, and a signal-to-noise ratio of $12.8$ after 1 round trip. In a second, monolithic cavity, we increase this lifetime to 1.75$\mu$s (35 round trips) with a memory efficiency of $12.7 \pm 0.2%$ (SNR of $7.0 \pm 0.2$) after 1 round trip. Fiber-based cavities for quantum storage at telecom wavelengths offer a promising route to synchronizing spontaneous photon generation events and building scalable quantum networks.

quant-ph