Title: Photo-induced Superconductivity and other stories Date/Time: 15-Apr, 04:00PM Venue: CQT Level 3 Seminar Room, S15-03-15
Abstract: In this lecture, I will discuss how coherent electromagnetic radiation at infrared and TeraHertz frequencies can be used to drive coherently and to large amplitudes interesting collective excitations in solids. I will discuss experiments in which superconducting fluctuations can be amplified by light at temperatures higher than the thermodynamic transition temperature.
CQT Colloquium by Noah Stephens-Davidowitz, MIT
Title: Benefits and risks of post-quantum cryptography from lattices Date/Time: 18-Apr, 04:00PM Venue: CQT Level 3 Seminar Room, S15-03-15
Abstract: Much of the internet relies on public-key cryptographic protocols to keep sensitive information private. Unfortunately, the protocols that we currently use are known to be vulnerable to attackers with quantum computers. Recent advancement in quantum computing has therefore started a bit of a rush to replace our current protocols with protocols that are secure against quantum attackers.
In this talk, I’ll describe the leading candidate for post-quantum cryptography: lattice-based cryptography. We’ll see a basic scheme, see the many benefits of lattice-based cryptography, and discuss some of the downsides and risks involved.
CQT Colloquium by Yoshiro Takahashi, Kyoto University, Kyoto, Japan
Title: Quantum Simulation with Ultracold Atoms in an Optical lattice Date/Time: 09-May, 04:00PM Venue: CQT Level 3 Seminar Room, S15-03-15
Abstract: Ultracold quantum gases with atomic Bose-Einstein condensates and Fermi degenerate gases offer important experimental platforms for various kinds of researches from precision measurement and quantum science. One of the interesting researches is the quantum simulation of strongly correlated many-body systems with ultracold quantum gases loaded into an optical lattice which is a periodic potential for atoms. First I will review some key experiments of quantum simulation performed with alkaline atoms. Then I report some of our recent experiments of quantum simulation with two-electron atoms of ytterbium(Yb) in an optical lattice which offer unique possibilities in the quantum simulation research. In particular, we successfully detect antiferromagnetic spin correlations of SU(N) Fermi gases of 173Yb in various lattice geometries, which is an important step in the study of novel SU(N) quantum magnetism and possible exotic superfluidity. Kondo impurity physics is also studied by a two-orbital system of a Fermi gas of 171Yb loaded in a novel optical lattice. We also study dissipative Bose and Fermi Hubbard model with the controlled two-body dissipation.
References  Antiferromagnetic Spin Correlation of SU(N) Fermi Gas in an Optical Superlattice, H. Ozawa, S. Taie, Y. Takasu, and Y. Takahashi ,Phys. Rev. Lett. 121, 225303 (2018), Antiferromagnetic Interorbital Spin-Exchange Interaction of 171Yb, K. Ono, J. Kobayashi, Y. Amano, K. Sato, and Y. Takahashi, arXiv:1810.00536,  Observation of the Mott insulator to superfluid crossover of a driven-dissipative Bose-Hubbard system, T. Tomita, S. Nakajima, I. Danshita, Y. Takasu and Y. Takahashi, Sci. Adv. 3, e1701513 (2017).
CQT Talk by Harry Buhrman, Centrum Wiskunde & Informatica (CWI)
Abstract: Quantum computers hold great promise as the next generation hardware. In the realm of computing several application domains have been found where quantum computers potentially outperform classical computers. However, this is not the only setting where quantum bits and quantum information have an advantage. When using the paradigm of quantum information in a communication setting several other applications have been found. These applications range from faster distributed communication protocols, cryptographic protocols and even applications to classical computers science and mathematics. I will give an overview of some of the results where I was involved and also discuss some new directions of research.
Abstract: Nima Alidoust leads the strategy team at Rigetti. During his talk, he will give a short introduction to Rigetti Computing. He will provide an overview of Rigetti's Quantum Cloud Services and a demo of its features and functionalities. He will also discuss what is in Rigetti's technology and product pipelines.
CQT Talk by Dharmraj Patil, IMRE, A*STAR
Title: Spin qubit in Silicon CMOS transistors for scalable architectures for quantum information processing Date/Time: 28-Mar, 04:00PM Venue: CQT Level 3 Seminar Room, S15-03-15
Quantum computing may provide a new way of information processing by exploiting the unique features of quantum mechanics. Several material systems have emerged as viable candidate for scalable architecture for quantum information processing which includes superconducting circuits, ion traps, spins confined in silicon quantum dots among others. Spin based qubits in silicon offers some unique advantages for development of scalable architectures over other material platforms. In this talk, I will discuss about hole spin qubit in silicon device fabricated on industrial-standard process. The device is a dual gate p-type transistor. At low temperatures, a double quantum dot is formed by using the two gates where spin information is encoded in one quantum dot whereas the second quantum dot is used as a qubit read-out. Qubit initialisation and read-out is performed using spin-to-charge conversion via Pauli spin blockade (PSB). Electrical control of hole spin qubit is achieved by microwave modulation of one of the gates. Taking advantage of small quantum dots in our device along with temperature independent spin read-out via PSB, we demonstrate hole qubit can be operated as high as 1 Kelvin. Our result opens a viable path to qubit scaling up by exploiting the CMOS platform.