The Periodic Phase Modulation of the Order Parameter Is Essential to Construct the Andreev Interferometer

Periodic phase modulation of regular parameters is important to construct Andreev interferometers. Please refer to figure \ ref {fig1} (a). We consider the Y junction near the FF superconductor. It introduces a finite pair of potentials on both channels. Specifically, all channels are set along the $ x $ direction, and the space spacing in the $ y $ direction is $ h $. The pairing of FF superconductors occurs with a finite momentum $ \ bf {Q} $ = $ (Q_x, Q_y) $ and the order parameter has the form $ \ Delta e. $ Is a pair of $ s $ waves.

For interferometers, the phase shift method has ambiguity of distance since the distance from the phase periodically changes. However, since the frequency modulation is much smaller than the optical frequency, the frequency is much greater than the frequency in the interferometer. Furthermore, blur can be easily removed, for example by measuring at two different modulation frequencies. A field programmable gate array (FPGA) is an IC that includes an array of identical logic blocks with programmable interconnections. It can also be classified as one of programmable logic devices (PLD). Still other types of PLDs are Simple Programmable Logic Device (SPLD) and Complex Programmable Logic Device (CPLD). Users can program functions implemented by each logic block and connections between blocks. The FPGA revolutionized the prototype design and design method. The flexibility provided by the reprogrammable FPGA enhances the design process

In the telecommunications field, modulation is the process of using it to change the periodic waveform (ie tone) to send a message. Normally, the carrier signal (usually a sine wave) has a higher frequency than the input signal. Amplitude, phase and frequency are three important parameters of a sine wave. These parameters can be modified based on the low frequency information signal to obtain the modulated signal. Amplitude modulation (AM), frequency modulation (FM) and phase modulation are the most common analog modulation techniques. Radio and television stations usually use AM or FM. More complex modulation formats are phase shift keying (PSK), amplitude shift keying (ASK) and frequency shift keying (FSK), which are three basic digital modulation techniques.

As with analog modulation, carrier modulation parameters such as phase, frequency, amplitude and so on in a digital modulation system vary depending on the information signal. Thus, there are three basic modulation schemes for digital modulation, such as amplitude shift keying (ASK), frequency shift keying (FSK), and phase shift keying (PSK). These technologies have various variations and combinations. The combination of ASK and PSK is also called QAM (Quadrature Amplitude Modulation). Due to technological advances and limitations of analog modulation, most satellites currently use digital modulation technology, which is superior to analog modulation such as improved performance, efficiency of error detection and correction, signal to noise ratio. Therefore, the focus of this white paper is mainly in various types of digital modulation system.