Although fault-tolerant quantum computation theoretically promises revolutionary benefits for computational science, the hardware development of a scalable fault-tolerant quantum computer is still in its infancy. In this talk, we will demonstrate near-term benefits of quantum or quantum-inspired computation from our two recent works [1-2]. First, using Quantum Alternating Operator Ansatz...

Motivated by the current technology of solid-state qubits, which is one of the promising platforms for quantum computing, we are interested in the effects of random charge noises and how they can result in qubit decoherence. In this work, we model the charge noise as a random telegraph process (RTP), or a noise described by a two-state fluctuator, and analyze theoretical formulas for the RTP....

Machine learning techniques have been widely used for many complex systems including quantum systems with noisy environments. In this work, we are interested in a system of qubits affected by the random-telegraph noise that could destroy the qubit coherence. We construct a theoretical model including one logical qubit and one probing qubit, the latter of which can be measured at various times...

One of the main obstacles for implementing qubits in real experiments is the detrimental effects of environmental noises. Qubits in noisy environments can decohere quickly, i.e., losing their capability in processing quantum information. In this work, we are interested in analyzing the decoherence and possible ways to correct the phase errors due to the Gaussian white-noise. We consider a...

Quantum annealing is an optimization method conventionally performed in an adiabatic fashion. Adiabatic quantum annealing (AQA) gradually changes the Hamiltonian so that the system stays in an instantaneous ground state of the Hamiltonian at all times. However, this slow process could hamper computational speedup. In contrast, diabatic quantum annealing (DQA) allows transitions between the...

Quantum computing is an interesting research and can be applied to many research areas, such as machine learning, optimization, and especially quantum simulation. In this work, we simulated the ground state energy of diatomic molecules: O2 and CO. We designed the ansatz for symmetric diatomic molecule, which is the O2 and asymmetric diatomic molecule, which is the CO. The designed quantum...

We reanalyze the problem of a 1D Dirac single-particle colliding with the electrostatic potential step of height $V_{0}$ with an incoming energy that tends to the limit point of the so-called Klein energy zone, i.e., $E\rightarrow V_{0}-\mathrm{m}c^{2}$, for a given $V_{0}$. In this situation, the particle is actually colliding with an impenetrable barrier. In fact, $V_{0}\rightarrow...

Quantum emitters (QEs) play crucial roles in quantum technology applications, especially for quantum key distribution. Recently, color-center defects in a two-dimensional hexagonal boron nitride (hBN) have revealed many promising properties, such as high brightness, operation under room temperature, and broad emission wavelengths, demonstrating that they are attractive candidates for QEs. Thus...

The determination of the refractive index (RI) and concentration of ternary mixture of glucose, ethanol and water is demonstrated by smartphone platform based on the detection of the refractive index by using surface plasmon resonance (SPR) principle. The optical coupler has been specially designed for coupling the light from smartphone screen to excite SPR on the thin gold layer in contact...

Quantum gas microscope is a powerful tool for studying complex atomic many-body quantum systems in optical lattices with a high-resolution imaging. This tool is used to investigate the interplay between charges and spins, which involves many exotic phenomena. In this talk, we will discuss about the utilization of quantum gas microscope of ultracold fermions ( $^6$Li) in optical lattices for...

Passive vibration isolation has been extensively used to mitigate a sensitive object from unwanted motions. It is a simple configuration consisting of an isolated object, a damper, and a spring in which excess vibration is suppressed by using its harmonic oscillator. However, resonance amplification at low-frequency range is a major weakness of this system. In this work, we add an active...

A vapor glass cell containing neutral atoms is an important tool for developing portable quantum devices. It can be used in quantum sensors, atom chips and cryptography devices quantum-related experiments involving quantum metrology, computation and communication. In this work, we find that the absorption coe๏ฌicient of rubidium atoms in our home-made vapor cell decreases as the input power...

One of the most sensitive methods for magnetic field measurement employs quantum phenomena at atomic level. We use the Doppler-free saturated absorption spectroscopy to reveal the hyperfine levels of the rubidium atoms which obscured by the thermal broadening, we able to observe the splitting of energy levels due to an external magnetic field. Furthermore, effect of polarization of the light...

The Fourier transform spectrograph (FTS) is an important tool that has been applied in many fields of research. In astronomical observation, the FTS has been used for analyzing stellar objects. Most of FTS that hav been designed and used with large telescope are based-on free space design to maximize flux throughput at the detector. However, the limited space at a focal plane of a large...

For fruit and flower transportation, ethylene gas is necessary to be detected. Various techniques are innovated, and the hollow core optical fiber is one of them. Its structure is suitable for flowing gas. So, it is used as a gas cell. This work proposed the nested hollow-core anti-resonant fiber made of Polyethylene Terephthalate (PET). Our structure is optimized to get the lowest loss at a...

Galactic cosmic rays (GCRs) are energetic charged particles, mainly protons originated in supernova remnants. Near Earth, GCR intensity ($n$) is subjected by modulation mechanisms in the solar wind, which are changed along the solar cycles (SCs) indicated by heliospheric magnetic field (HMF). We have used GCR count rates as observed by neutron monitors at low-to-high cut-off rigidities ($P_c$)...

We investigate the characteristic spectrum of Hydrogen atoms subjected to the gravitational wave (GW) produced by a compact binary inspiral, particularly the supermassive black hole binary (SMBHB). These atoms are assumed to be distributed in the sourceโs local wave zone. The gravitational wave is mathematically described by the quadrupole formula of the linearized theory of General...

Standard time and frequency are widely implemented in many systems: global navigation satellite system, high speed communication, and financial technology. Each application requires different accuracy and stability. Atomic clock has been used as the precise oscillator. In 1967, the energy level between two hyperfine ground states of Cesium 133 at 0 K has been defined as the standard unit of...

We build a quantum diamond spectrometer (QDS), outlined by Bucher et. al [1], to study the fluorescence of the nitrogen-vacancy (NV) center in diamond, a quantum defect that can be used as a qubit or quantum sensor. The QDS has several advantages to a traditional confocal microscopy, particularly in terms of measurement speed. The setup consists of a green laser excitation onto the diamond...

Nitrogen Vacancy (NV) center is a defect in a diamond with unique optical transitions in the visible wavelength that is spin-dependent, allowing it to be utilized as an optical qubit or as a magnetometer. Our work primarily focus on magnetic field sensing with NV center, as they offer high sensitivity and high spatial resolution at the nanoscale level, along with ability to simultaneously...

Optical Coherence Tomography Angiography (OCTA) is a non-invasive imaging technique for microvasculature visualization. OCTA does not require injection of exogenous contrast agents, or fluorescent dye into blood circulation, which may cause allergic reactions as in fluorescein angiography (FA) and indocyanine green angiography (ICGA). OCTA differentiate blood vessel from static tissues by...

Inspired by random walks on graphs, the diffusion map (DM) is a class of unsupervised machine learning that offers automatic identification of low-dimensional data structure hidden in a high-dimensional data set. In recent years, among its many applications, the DM has been successfully applied to discover relevant order parameters in many-body systems, enabling automatic classification of...

Phase change correction is an important correction value of the end effect in an optical interferometry system. Normally, this value is used to compensate for gauge block measurement by an optical interferometry system based on ISO 3650:1998. Quartz plates and three different types of gauge block: steel, ceramic, and tungsten carbide were used in this study. Two different interferometric...