Hole Spin Resonance and Spin-Orbit Coupling in a Silicon Metal-Oxide-Semiconductor Field-Effect Transistor

Abstract

We study hole spin resonance in a p-channel silicon metal-oxide-semiconductor field-effect transistor. In the sub-threshold region, the measured source-drain current reveals a double dot in the channel. The observed spin resonance spectra agree with a model of strongly coupled two-spin states in the presence of a spin-orbit-induced anti-crossing. Detailed spectroscopy at the anticrossing shows a suppressed spin resonance signal due to spin-orbit-induced quantum state mixing. This suppression is also observed for multi-photon spin resonances. Our experimental observations agree with theoretical calculations.PACS numbers: 73.63. Kv, 73.23.Hk, The silicon-based metal-oxide-semiconductor fieldeffect transistor (MOSFET) is a key element of largescale integrated circuits that are at the core of modern technology. Looking into the future, a universal faulttolerant quantum computer also requires a huge number of physical qubits, on the order of 10 8 or more [1,2]. As such, a qubit integrated with the standard Si MOS-FET architecture would be truly attractive from the perspectives of scaling up and leveraging existing technologies. One example of such a qubit is the spin of an impulity/defect in the channel of a Si MOSFET. Indeed, spin qubits defined in Si nano-devices are not only compatible with current silicon technology, but are also known to be one of the most quantum coherent among known qubit designs [3][4][5][6][7][8][9][10][11][12][13].Although there are many studies of impurities and defects in Si [14], single impurity/defect in the channel of a Si MOSFET has only recently been studied experimentally, by single-electron tunneling [15][16][17][18][19]. Spins of such defects are difficult to characterize because of their weakly-interacting nature. Controlling the spins of impurities in a MOSFET, as well as in a gate-confined quantum dot, can be achieved much more easily in a pchannel MOSFET than an n-channel. The reason is that the larger spin-orbit interaction (SOI) of a hole (-like) spin enables the spin resonance by an oscillatory electric field, instead of a magnetic field, at microwave frequencies under typical sub-Tesla static magnetic fields. Such electrically-driven spin resonance (EDSR) has been demonstrated in III-V devices [20][21][22][23], as well as in Si [24][25][26], while SOI effects in gate-confined Si quantum dots have been investigated in the spin blockade region [27]. However, systematic investigations of EDSR * E-mail address: k-ono@riken.jp † these authors contributed equally to this work under the direct influence of SOI have not been performed in Si, the material that provides an ideal stage for studying SOI due to the minor presence of nuclear spins.In this work we study sub-threshold transport and EDSR in a short p-channel Si MOSFET, and quantitatively reveal the effects of SOI and EDSR on lifting the spin blockade. Specifically, our transport measurements demonstrate that there are two effective dots in the channel, which allow us to identify a spin blockade regime and explore spin reso...

Transport spectroscopy of a spin-orbit-coupled spin to a quantum dot

“…The current confirms the presence of appreciable spin orbit interaction (SOI) whose strength is controlled by the applied voltage to a gate electrode. Similar magneto-conductance measurements through a double dot formed in the channel of a silicon transistor device have demonstrated the appearance of extra peaks in the leakage current as a result of an unwanted spin interacting with the double dot in the presence of spin orbit coupling 5 . An impurity tunnel-coupled to a single quantum dot in a silicon-germanium heterostructure has also been reported 6 , and this situation may also be relevant to other silicon devices which make use of dopants to confine spins 7,8 .…”

“…One very well-known case is the presence of many nuclear spins, e.g., on the order of 10 4 − 10 5 , causing the host spins to decohere due to the Overhauser field 1,3 . However, experiments have demonstrated that even a single spin can affect the device operation 4,5 . For example, electrical transport measurements in a carbon nanotube double dot have revealed that an impurity spin attached to the nanotube modifies the expected leakage current in the spin blockade regime 4 .…”

“…In these dot systems the spin is unintentionally coupled to the dot, but fullerene and in general molecular spins intentionally coupled to dot systems can be fabricated in the laboratory and have shown exceptionally long coherence times 9 . The importance of the SOI has been identified in various systems ranging from optical 10 to semiconductor nanostructures 4,5,[11][12][13] . In double quantum dots the SOI has been employed for spin manipulation, e.g., in electrically-driven coherent spin rotations of a pair of qubits 12,13 .…”

“…Some of these ideas are also applicable to double quantum dots driven by external fields 21,22 . The model we adopt here is motivated by experiments that have probed the SOI in few-spin systems 4,5,[11][12][13] . Thus, it is mostly concerned with the role of the SOI in the interaction between the spin and the dot.…”

Spin Seebeck effect and thermal spin galvanic effect in Ni80Fe20/p-Si bilayers

“…The metal-semiconductor interface will lead to electron gas (EG) at the interface having thickness similar to the spin diffusion length as shown in Figure 3 d. The charge potential in the EG gives rise to strong Rashba SOC, which is the underlying cause of SSE, thermal SGE and SOT observed in this study. The spin orbit coupling due to lack of inversion symmetry in Si metal-oxide semiconductor field effect transistor (MOSFET) has been reported using magneto-transport behavior in two-dimensional electron gas (2DEG) [47][48][49][50] and using spin resonance measurements 51 .…”