Property and equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 25,225		$ 25,225		$ 25,050
Less: Accumulated depreciation	(22,453)		(22,453)		(21,801)
Property and equipment, net	2,772		2,772		3,249
Depreciation expense	309	$ 344	705	$ 747
Quantum computer systems
Property, Plant and Equipment [Line Items]
Total property and equipment	13,425		13,425		13,425
Lab equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	6,681		6,681		6,645
Computer equipment
Property, Plant and Equipment [Line Items]
Total property and equipment	3,352		3,352		3,305
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property and equipment	1,075		1,075		1,074
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Total property and equipment	318		318		316
Construction-in-progress
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 374		$ 374		$ 285