Jong-Phil Hong

A 2.2-mW Backgate Coupled

This letter presents a backgate coupled quadrature voltage-controlled oscillator (QVCO) which consists of a pair of current reused LC-VCOs. The proposed QVCO is designed for 2-GHz operation based on a 0.18-mum triple-well CMOS technology. Measurements show -102 and -124dBc/Hz at 100-kHz and 1-MHz offset, respectively. Compared to the conventional QVCO, the proposed QVCO dissipates significantly lower power (1.74mA from a 1.25-V supply) while showing good 1/f3 close-in phase noise

LC

We demonstrate the advantages of an optical parity gate using weak cross-Kerr nonlinearities (XKNLs), quantum bus (qubus) beams, and photon number resolving (PNR) measurement through our analysis, utilizing a master equation under the decoherence effect (occurred the dephasing and photon loss). To generate Bell states, parity gates based on quantum non-demolition measurement using XKNL are extensively employed in quantum information processing. When designing a parity gate via XKNL, the parity gate can be diversely constructed according to the measurement strategies. In practice, the interactions of XKNLs in optical fiber are inevitable under the decoherence effect. Thus, by our analysis of the decoherence effect, we show that the designed parity gate employing homodyne measurement would not be expected to provide reliable quantum operation. Furthermore, compared with a parity gate using a displacement operator and PNR measurement, we conclude there is experimental benefit from implementation of a parity gate via qubus beams and PNR measurement under the decoherence effect.

Quadrature VCO With Current Reused Structure

A complementary cross-coupled differential Colpitts voltage controlled oscillator (VCO) is reported. The combination of gm-boosting and the complementary transistors allows record low power integrated VCO implementation. The proposed VCO and the corresponding parallel quadrature VCO (P-QVCO) are implemented using 0.25-μm CMOS technology for 1.8 GHz operation. Measurements for the VCO and P-QVCO show phase noise of -116.8 and -117.7 dBc/Hz at 1 MHz offset, while dissipating only 0.4 and 1.1 mA from a 0.9-V supply, respectively.

Analysis of optical parity gates of generating Bell state for quantum information and secure quantum communication via weak cross-Kerr nonlinearity under decoherence effect

We propose a controlled quantum teleportation scheme to teleport an unknown state based on the interactions between flying photons and quantum dots (QDs) confined within single- and double-sided cavities. In our scheme, users (Alice and Bob) can teleport the unknown state through a secure entanglement channel under the control and distribution of an arbitrator (Trent). For construction of the entanglement channel, Trent utilizes the interactions between two photons and the QD-cavity system, which consists of a charged QD (negatively charged exciton) inside a single-sided cavity. Subsequently, Alice can teleport the unknown state of the electron spin in a QD inside a double-sided cavity to Bob’s electron spin in a QD inside a single-sided cavity assisted by the channel information from Trent. Furthermore, our scheme using QD-cavity systems is feasible with high fidelity, and can be experimentally realized with current technologies.

360-µW/1 mW Complementary Cross-Coupled Differential Colpitts LC -VCO/QVCO in 0.25-µm CMOS

We design schemes to generate and distribute hybrid entanglement and hyperentanglement correlated with degrees of freedom (polarization and time-bin) via weak cross-Kerr nonlinearities (XKNLs) and linear optical devices (including time-bin encoders). In our scheme, the multi-photon gates (which consist of XKNLs, quantum bus [qubus] beams, and photon-number-resolving [PNR] measurement) with time-bin encoders can generate hyperentanglement or hybrid entanglement. And we can also purify the entangled state (polarization) of two photons using only linear optical devices and time-bin encoders under a noisy (bit-flip) channel. Subsequently, through local operations (using a multi-photon gate via XKNLs) and classical communications, it is possible to generate a four-qubit hybrid entangled state (polarization and time-bin). Finally, we discuss how the multi-photon gate using XKNLs, qubus beams, and PNR measurement can be reliably performed under the decoherence effect.

Implementation of controlled quantum teleportation with an arbitrator for secure quantum channels via quantum dots inside optical cavities

This paper presents a 219 GHz fundamental CMOS oscillator with a 2.08% DC-to-RF efficiency. The proposed structure oscillates at a high fundamental frequency by adopting a capacitive-load reduction technique. In addition, a differential-to-single (DTS) transformer increases the output power by combing the differential signals. The proposed oscillator is fabricated in a 65 nm CMOS process. The measurements show an output power of 0.5 mW at the fundamental oscillation frequency of 219 GHz, while consuming 24 mA from a 1 V supply voltage. This work presents a fundamental oscillator with a higher DC-to-RF efficiency compared to previous state-of-the-art generators between the 200 and 300 GHz frequency range.

Distribution of hybrid entanglement and hyperentanglement with time-bin for secure quantum channel under noise via weak cross-Kerr nonlinearity

A new resistance model for a Schottky Barrier Diode (SBD) in CMOS technology is proposed in this paper. The proposed model includes the n-well thickness as a variale to explain the operational behavior of a planar SBD which is firstly introduced in this paper. The model is verified using the simulation methodology ATLAS. For verification of the analyzed model and the ATLAS simulation results, SBD prototypes are fabricated using a 0.13㎛ CMOS process. It is demonstrated that the model and simulation results are consistent with measurement results of fabricated SBD.

A 219-GHz fundamental oscillator with 0.5 mW peak output power and 2.08% DC-to-RF efficiency in a 65 nm CMOS

We present a scheme to encode quantum information (single logical qubit information) into three-photon decoherence-free states, which can conserve quantum information from collective decoherence, via nonlinearly optical gates (using cross-Kerr nonlinearities: XKNLs) and linearly optical devices. For the preparation of the decoherence-free state, the nonlinearly optical gates (multi-photon gates) consist of weak XKNLs, quantum bus (qubus) beams, and photon-number-resolving (PNR) measurement. Then, by using a linearly optical device, quantum information can be encoded on three-photon decoherence-free state prepared. Subsequently, by our analysis, we show that the nonlinearly optical gates using XKNLs, qubus beams, and PNR measurement are robust against the decoherence effect (photon loss and dephasing) in optical fibers. Consequently, our scheme can be experimentally implemented to efficiently generate three-photon decoherence-free state encoded quantum information, in practice.

A New Resistance Model for a Schottky Barrier Diode in CMOS Including N-well Thickness Effect

A dual-peak maximum achievable gain core design technique is proposed. It has been adopted into a 4-stage wideband amplifier. Implemented in a 65nm CMOS, the amplifier achieves 3dB bandwidth of 30GHz (230∼260GHz), gain of 12.4±1.5dB, and peak PAE of 1.6% while dissipating 23.8mW, which corresponds to the widest bandwidth and highest gain per stage among other reported CMOS amplifiers operating above 200GHz.

Preparation of quantum information encoded on three-photon decoherence-free states via cross-Kerr nonlinearities

A high output power and high fundamental frequency CMOS oscillator is presented in this paper. To increase output power, the source inductor at the core transistor is coupled with the drain inductor at the buffer transistor through a transformer. A capacitive load reduction circuit (CLRC) is also used to increase the fundamental oscillation frequency. The proposed single-core fundamental oscillator is implemented using 65 nm CMOS technology. The measurement results show a fundamental frequency of 194 GHz and maximum differential output power of 1.85 mW.