Enhancement of microwave fields in pulse EPR of quantum paraelectrics

0580135 - FZÚ 2024 RIV US eng J - Journal Article
Laguta, Valentyn - Bovtun, Viktor - Kempa, Martin - Laguta, O. - Neugebauer, P. - Simenas, M. - Banys, J. - Kamba, Stanislav
Enhancement of microwave fields in pulse EPR of quantum paraelectrics.
Applied Physics Letters. Roč. 123, č. 21 (2023), č. článku 214001. ISSN 0003-6951. E-ISSN 1077-3118
R&D Projects: GA ČR(CZ) GA23-05578S
Institutional support: RVO:68378271
Keywords : EPR * spin qubits * microwave * quantum paraelectrics
OECD category: Condensed matter physics (including formerly solid state physics, supercond.)
Impact factor: 4, year: 2022
Method of publishing: Open access

We study the effect of the high polarizability of KTaO3 and SrTiO3 quantum paraelectrics on local electric and magnetic field components of microwaves (MW) at Fe3+ and Mn2+ paramagnetic ions. It is found that the power of MW pulses used in coherent spin manipulation at nanoseconds time scale decreases to milliwatts as compared to the tens-hundreds of watts usually used for spins in conventional materials. The amplification of MW fields is related to the very high dielectric permittivity of quantum paraelectrics at GHz frequencies and temperatures below 20 K. This creates the large induced polarization and secondary MW magnetic field. The low MW power for excitation of spin transitions in quantum paraelectrics eliminates the requirement of expensive high-power MW equipment. This approach also allows to globally control spin qubits in tandem with integrated devices based on conventional semiconductor MW circuits working at mW powers.
Permanent Link: https://hdl.handle.net/11104/0348901